AN ACCOUNT OF THE CRUSTACEA OF NOR WAY WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES BY G. O. SARS VOL. VII COPEPODA SUPPLEMENT PARTS I & II CALANOIDA, HARPACTICOIDA (part) WITH ;6 AUTOTYPIC PLATES BERGEN PUBLISHED BYTHE BERGEN MUSEUM SOLO BY ALB. CAMMERMEYERS'S FORLAG, CHRISTIANIA 1919 INTRODUCTION. The considerable number of additional species observed during the latter years has induced me to publish a supplementary Volume to the Copepoda, containing descriptions and figures of these species, and embracing all the 3 leading divisions treated of in the 3 preceding Volumes. The far greater number of these species has been derived from the extensive division Har- pacticoida; but also of Calanoida and Cyclopoida several interesting forms are added in the present Volume. Most of the species here described have been picket up from bottom-samples taken at different times, and chiefly in 2 local- ities on our southern coast, viz., Korshavn and Riser, some also from mixed collections of Copepoda made in the same localities. It is evident that the study of the present order of Crustacea still remains to be a very promising one, and I do not doubt that continued investigations in other places of our extensive coast will reveal many additional forms worthy of note. 1 Crustacea. Calanoida. Fam. Phaennidae. Gen. Xanthocalanus, Giesbr. Remarks. Of this genus, in addition to the 2 species originally recorded by Giesbrecht from the Mediterranean, several new forms have been described in recent time from the northern Ocean, some of them being, however, so nearly related, the ones to the others, that they, without a very close examina- tion, may easily be confounded. As moreover, owing to the great britlleness of the appendages, most specimens obtained are more or less defective, the determination of the species belonging to the present genus is connected with no small difficulty. I have myself formerly, under the name X. borealis, con- founded 3 different species. The one originally described by the present author under that name from the Nansen Expedition is a true arctic form, which does not occur off the coast of Norway. It has recently been identified, though with some doubt, by Mr. With with X. hirtipes Vanhoeffen. The Norwegian form recorded in Vol. IV of the present work as X. borealis is quite certainly not identical with the arctic species, differing, as it does, both by its much inferior size and by the rather unlike structure of the last pair of legs. I was seduced to this erroneous identification by the occurrence in my material of some few specimens, in which the last pair of legs, by the complete fusion of the 2 outer joints and the presence of only 3 apical spines, exhibited a certain resemblance to these appendages in the arctic form. These specimens I supposed to be young, not yet fully developed females, and that accordingly the last pair of legs changed their character according to age. This supposition has, however, turned out to be quite wrong. I have subsequently found fully adult specimens with the very same structure of the last pair of legs, and I have convinced myself that they are referable to a well defined species, which will be described below. For the other Norwegian species I propose the name X. fallax. A 3rd Norwegian species has been described in the present work as X. propinqvus. The most reliable character for distinguishing the species of the present genus is unquestionably the structure of the last pair of legs. 1. Xanthocalanus minor, Giesbr. (Pi. I). Xanthocalanus minor, Giesbrecht, Fauna and Flora des Golfes von Neapel: Pelagische Cope- poden, p. 286 (footnote), Pi. 12, Fig. 32. Specific Characters. Female. Body moderately slender, with the anterior division oblong oval in form, greatest width not nearly attaining half the length and occurring somewhat behind the middle; dorsal face only slightly vaulted. Cephalosome nearly as long as the exposed part of the trunk, and exhibiting behind the middle dorsally a distinct transverse suture; anterior extremity narrowly rounded. Rostral filaments of moderate length and abruptly reflexed. Last trunkal segment completely coalesced with the preceding one; lateral lobes triangularly produced, and extending somewhat beyond the middle of the genital segment. Urosome comparatively short, scarcely exceeding in length 1 U of the anterior division; genital segment only slightly protuberant below, and about the length of the 2 succeeding segments combined; anal segment very small. Caudal rami scarcely longer than they are broad; apical setae well developed and somewhat divergent, the innermost but one, as usual, considerably longer than the others. Anterior antennae rather elongated, ex- tending, when reflexed, to the end of the caudal rami. Posterior antennae and oral parts almost exactly as in X. fallax. Natatory legs likewise of a very similar structure, though having the spinules of the inner ramus fewer in number. Last pair of legs, however, rather unlike those in the said species, the outer 2 joints being, as in X. borealis, completely coalesced to an elongated some- what curved piece armed at the end with only 3 comparatively short, subequal spines, edges of the piece nearly smooth, with only a few cilia at the outer curvature. Body in the living animal highly pellucid, with only a faint rosy pig- ment at the end of some of the segments. Length of adult female reaching to 2.70 mm. Remarks. The figure given by Giesbrecht of the last pair of leg in his X. minor agrees pretty well with those appendages in the above-described form, and I think therefore that I am right in identifying both, though no other figures were given by Giesbrecht, nor any description of the species. The length of the body is said to be only 1.20 mm.: but I suppose that an exact measurement may have been rendered difficult by the bad condition of the solitary specimen observed by that author. As above stated, the present species was formerly confounded by me with X. fallax (at that time recorded as X. borealis), to which species it cer- tainly bears a close resemblance. It is however rather inferior in size and of somewhat more slender form of body, differing moreover in the greater length of the anterior antennae, and more particularly in the structure of the last pair of legs, which more resembles that in the arctic species, X. borealis. In the latter, however, these appendages are everywhere densely hirsute, and the apical spines are much stronger, nearly claw-like. Occurrence. Adult female specimens of the present species have been found in 3 different localities of the Norwegian coast, viz., at Riser, Stavanger, and in the upper part of the Trondhjem Fjord. In all 3 localities it occurred only occasionaly and in comparatively shallow water. Distribution. Mediterranean (Giesbrecht). Fam. Stephidae. Gen. Stephos, Scott. Remarks. Two well-defined species of this genus have been de- scribed in Vol. IV of the present work. A 3rd species is now added, to be described below. 2. Stephos minor, Scott. (PL II). Stephos minor, T. Scott, Tenth Ann. Report of the Fishery Board for Scotland, Part III, p. 245, PI. VIII, figs. 113. Specific Characters. Female. Body resembling in shape that of S. Scotti G. O. Sars, the anterior division being regularly elliptical in outline and evenly vaulted dorsally; greatest width about half the length. Cephalic segment very large, with the front obtusely truncated and exhibiting no trace of rostral filaments. Lateral parts of last trunkal segment perfectly symmetrical and not lamellarly expanded. Urosome equalling in length about l /3 of the anterior division; genital segment somewhat protuberant below, and about the length of the 2 succeeding segments combined. Caudal rami scarcely longer than they are broad; apical setae rather slender, the innermost but one, as usual, the longest and considerably exceeding the length of the urosome. Anterior antennae comparatively shorter than in S. Scotti, scarcely extending, when reflexed, beyond the genital segment. Posterior antennae, oral parts and natatory legs of a structure very similar to that in 5. Scotti. Last pair of legs rather small, with the distal joint conical in form, and only armed with a single denticle inside at some distance from the tip; outer edge with a small bristle opposite the denticle. Male much smaller than female, with the urosome more slender and 5-articulate. Last pair of legs built on the same type as in the other species, though exhibiting well-marked specific differences, as seen from the figure here given. Body in both sexes highly pellucid and without any obvious pigment. Length of adult female 0.73 mm., of male 0.60 mm. Remarks. The present species, first described by Scott, is nearly allied to S. Scotti G. O. Sars, but of much smaller size, and moreover well disting- uished by the somewhat storter anterior antennae and by the structure of the last pair of legs in both sexes. Occurrence. Several specimens of this form were taken in a single place at Korshavn from a depth of about 15 fathoms. I have also found it occasionally at Riser in about the same depth. Distribution. Scottish coast (Scott). Gen. Parastephos, G. O. Sars. Remarks. This genus was established in the year 1903 by the present author, to include a peculiar Copepod, of which at that time only a solitary male specimen was obtained. Subsequently Mr. Scott found also the female, and the perplexing characters distinguishing this sex fully prove the validity of the present genus. I have been fortunate enough to find a few female specimens off the Norwegian coast, and I am thus enabled to confirm the statements given by Scott about this sex. 3. Parastephos pallidus, G. O. Sars. (Pi. ill). Parastephos pallidus, G. O. Sars, Account of the Crustacea of Norway, Vol. IV, p. 65, Pi. XLIV. Specific Characters. Female. Body very slender, with the two chief divisions sharply marked off from each other, the anterior one regularly oblong oval in form. Cephalic segment with a faint transverse suture behind the middle dorsally; front blunted, without any traces of rostral filaments. Last truncal segment completely fused with the preceding one, and having the lateral parts only slightly produced. Urosome very powerfully developed, equalling in length about 2 /a of the anterior division, its 3 anterior segments expanded behind to elevated circular ridges densely clothed with delicate recurved spinules; genital segment scarcely at all protuberant below and, as usual, the largest, though not much exceeding in size the succeeding segment; anal segment well developed and of sub-cylindrical form; without any elevated ridge behind. Caudal rami scarcely longer than they are broad; apical setae slightly divergent, the innermost but one on left ramus remarkably produced, being nearly twice as long as that on the right ramus. Anterior antennae of the very same structure as in the male, and extending, when reflexed, to the end of the genital segment. Posterior antennas and oral parts exactly as in the male. Natatory legs of quite normal structure and resembling those in the genus Stephos. Last pair of legs likewise built on the same type as in that genus, but of comparatively much larger size and pronouncedly asym- metrical, the left leg being considerably longer than the right; distal joint in both legs conically produced and armed outside with a row of 12 15 coarse denticles, the proximal of which is somewhat remote from the others and of larger size. Body in the living animal semipellucid, of an uniform whitish grey colour, without any obvious pigmentation. Length of adult female reaching to 2.20 mm. Remarks. Of this form, as above mentioned, only the male sex was formerly observed by me. The female, as usual, is of considerably larger size, and exhibits a most anomalous appearance by the powerful development and peculiar armature of the urosome. The last pair of leg are also remarkable by their comparatively large size, and more particularly by their conspicuous asymmetry, also observed by Scott. Another asymmetry, not mentioned by that author, is found in the extraordinary length of one of the caudal setae on left side. On the other hand has the asymmetry described by the present author in some of the natatory legs of the male specimen at first obtained proved to be quite accidental, as no such asymmetry was found in another male subsequently obtained. Occurrence. The originally described male specimen was taken at Skjerjehavn, outside the Sogn Fjord. I have subsequently obtained 3 additional specimens of this remarkable form, 2 adult females and one male. Of these the one female was taken at Kopervik, south west coast of Norway, the other female and the male specimen at Riser, the depth in both localities ranging from 50 to 100 fathoms. Distribution. Scottish coast (Scott). Farn. Pseudocyclopiidee. Gen. Pseudocyclopia, Scott. Remarks. Only a single species of this genus, P. stephoides Thompson, has hitherto been recorded from the Norwegian coast. I am now enabled to add 2 other species, both described at an earlier date by British authors, and it is very probable that also the remaining 2 species, P. minor and P. caudata Scott, will on a further investigation be found to belong to the fauna of Norway. 4. Pseudocyclopia Giesbrechti, Wolfenden. (PI. IV, PI. V, fig. 1). Pseudocyclopia Giesbrechti, Wolfenden, Journal of the Marine Biological Association, Vol. VI, No. 3, p. 370, PL IV. Specific Characters. Female. Body rather short and stout, with the anterior division considerably vaulted above, and somewhat compressed, ex- hibiting in the dorsal aspect a narrow oblong form, with the greatest width scarcely attaining half the length. Cephalic segment very large and evenly curved in front; rostral prominence triangular, deflexed. Last truncal segment united with the preceding one and deeply emarginated behind in the middle, lateral parts obtusely rounded. Urosome about equalling in length Vs of the anterior division; genital segment only slightly protuberant below and about the length of the 2 succeeding segments combined. Caudal rami short, being scarcely longer than they are broad, and somewhat obliquely truncated at the 8 end; apical setae rather strong and partly exhibiting a dense annulation. An- terior antennae only slightly exceeding half the length of the cephalic segment, and composed of 17 joints, the 1st of which, apparently formed by the junction of the 6 or 7 proximal joints, is very large, almost occupying half the length of the antenna. Posterior antennae with the terminal part (inner ramus) com- paratively shorter than in P. stephoides, though a little longer than the outer ramus; the latter 6-articulate, with the 2nd joint somewhat dilated, oval in form, and provided outside with 3 setae, the 3 succeeding joints very small. Oral parts of the structure characteristic of the genus. Natatory legs likewise built on the same type as in the other species, though the rami appear some- what more slender than in P. stephoides and more distinctly spinulose at the end of the joints, those of 4th pair being moreover densely covered with small prickles. Last pair of legs rather short and stout, with the last joint scarcely longer than the middle one and somewhat hand-shaped, terminating in 3 strong diverging digitiform spines of equal length, the outermost one distinctly defined at the base, whereas the other 2 form the immediate continuation of the joint; all 3 spines, as also partly the surface of the joint, coarsely spinulose. Male, as usual, smaller than female and having the urosome more slender and distinelly 5-articulate. Antennae, oral parts and natatory legs scarcely different from those parts in female. Last pair of legs, however, con- spicuously transformed and very asymmetrical; right leg long and slender, termi- nating in a somewhat flexuous point; left leg much shorter, but with the 1st joint considerably tumefied, nearly globular in form, 2nd joint tapered distally and provided at the end with a well-marked rudiment of an appendicular ramus, 3rd joint very narrow and armed at the end with a slender movable claw, outside which are attached a bundle of 3 delicate and closely superposed lamellae. Colour of the living animal not yet ascertained. Length of adult female reaching to 0.90 mm., that of male to 0.79 mm. Remarks. The present species was first described by Mr. Wolfenden from a solitary female specimen taken off the Shetland isles. Subsequently T. Scott found the same species also off the Scottish coast, and has given a figure with some details of a male specimen. It may easily be distinguished from P. stephoides by the comparatively shorter and stouter_ form of the body and more particularly by the structure of the last pair of legs in bot sexes. As these appendages were somewhat damaged in the male specimen examined by Scott, the figure he gives of them has turned out to be rather imperfect. Moreover the right leg is described as the left, and vice versa. Occurrence. Several specimens of this form have been picked up from bottom-samples taken at Korshavn from a depth of about 60 fathoms muddy sand. It also occurs occasionally at Ris0r in about the same depth. Distribution. Shetland (Wolfenden), Scotish coast (Scott). 5. Pseudocyclopia crassicornis, Scott. (PI. V, fig. 2). Pseudocyclopia crassicornis, T. Scott, Tenth Ann. Report of the Fishery Board for Scotland, Part III, p. 246, PI. VII, figs. 1529. Specific Characters. Female. Very like the preceding species, as to the general appearance of the body, but of much smaller size. Anterior antennae comparatively shorter, scarcely exceeding half the length of the cephalic segment, and rather thick at the base, being composed of 16 joints, the 1st of which is very large, fully as long as the remaining part of the antenna, and, in addition to the usual short marginal setse, provided with 3 comparatively large aesthetasks. Posterior antennae with the penultimate joint (1st joint of the inner ramus) somewhat dilated in the middle, subfusiform in shape, outer ramus resembling in structure that of the preceding species and a little shorter than this joint. Oral parts and natatory legs of the usual struc- ture. Last pair of legs with the middle joint very short, nearly circular in form; terminal joint much larger, occupying more than half the length of the leg, and armed at the somewhat obliquely truncated extremity with 3 slender spines, the innermost of which is much the longest and, like the middle one, not defined from the joint at the base. Spermatophore, attached to the genital segment, of unusually large size and curving upwards along the dorsal face of the urosome. Male of still smaller size than female, and differing from it in a similar manner to that in the preceding species. Last pair of legs, however, of a somewhat simpler structure; the left leg having no trace of an appendicular ramus at the end of the 2nd joint, and only a single lamella outside the apical claw, which is rather small. Colour in the living animal not yet ascertained. Length of adult female scarcely exceeding 0.71 mm.; that of male 0.68 mm. Remarks. This form was described by T. Scott in the year 1892 as the type of his genus Pseudocyclopia. It is of much smaller size than the preceding species, and moreover easily distinguished by the shorter and thicker anterior antennas and by the somewhat different structure of the last pair of legs in both sexes. 2. Crustacea. 10 Occurrence. I have found this form in the same localities and at about the same depth as the preceding species. At Riser only one or two speci- mens were obtained, whereas at Korshavn this form seems to be rather abundant in some places. Distribution. Scottish coast (Scott). Fam. Platycopiidae. Gen. Platycopia, G. O. Sars, 1911. Generic Characters. General form of body resembling that of Pseudo- cyclopia. Last trunkal segment, however, well defined from the preceding one, and urosome composed in both sexes of only 4 segments. Anterior antennae short and stout, though composed of rather a great number of articulations, and only slightly differing in the two sexes. Posterior antennae with the outer ramus much larger than the inner. Oral parts considerably deviating in struc- ture from the usual Calanoid type. Anterior lip narrowly produced at the end. Mandibles with the masticatory part only slightly expanded, palp comparatively slender, with the outer ramus larger than the inner. Maxillae with the masti- catory lobe very coarsely built, palp comparatively less fully developed than in most other Calanoida. Anterior maxillipeds cyclopoid in structure, the outer joints being armed with stout unguiform spines. Posterior maxillipeds more resembling those in other Calanoids. 1st pair of legs rather unlike the suc- ceeding ones, with both rami imperfectly developed and without true spines; the remaining pairs very strongly built, with the rami broad and flattened, the outer one the larger, and having 2 successive spines outside the 1st joint; natatory setae for the most part converted to short flattened spines. Last pair of legs built on the very same type as the preceding ones; those of male having the outer ramus slightly transformed and alike on both legs. Remarks. This genus was established by the present author in the year 1911, to include a remarkable deep-water Calanoid, P. perplexa, the closer examination of which revealed a most perplexing mixture of char- acters tending on the one side to the genus Pseudocydopia, on the other side to Pseudocyclops, though these 2 genera, according to the definition given by Giesbrecht, in reality belong to 2 very different sections of the Calanoida, the 11 first to the Atnphascandria, the 2nd to the f-ieterarthmndria. I think that this premary division of the Calanoida proposed by Giesbrecht, and now generally accepted by carcinologists, may turn out to be a less natural one, and I am also now in doubt about the validity of the 3rd intermediate section, Isoker- andria, added in my earlier account of the Calanoida (Vol. IV of the present work). Indeed, it seems to be very difficult to decide, to which of these 3 sections the present genus should be referred. 1 ) Two nearly allied species of this remarkable genus will be described below. 6. Platycopia perplexa, G. O. Sars. (PI. VI, PI. VII, fig. 1). Platycopia perplexa, G. O. Sars, Archiv f. Mathem. & Naturvidenskab, Vol. XXXI, No. 7, p. 4, PI. I & II. Specific Characters. Female. Body short and stout, with the anterior division greatly vaulted above and somewhat compressed, the greatest width not fully attaining the hight and about equalling half the length. Cephalic segment very large, occupying nearly half the length of the whole body, and evenly curved in front; inferior edges somewhat bulging in their anterior part, rostral projection comparatively short and acutely pointed at the end. The 4 succeeding segments densely crowded and of about equal length, though diminishing somewhat both in height and width; last segment deeply emarg- inated behind in the middle and having the lateral lobes rounded at the end. Urosome scarcely exceeding in length 1 /z of the anterior division and narrow cylindrical in shape; genital segment comparatively small and only slightly dilated; penultimate segment the longest and produced at the end dorsally to 2 juxtaposed lanceolate lappets superposing the anal segment and apparently replacing the usual anal opercle; last segment much smaller than any of the others. Caudal rami short, being only slightly longer than they are broad; seta of outer edge small and attached somewhat in front of the middle; apical setae rather unequal in length, the innermost but one being, as usual, the : ) At this occasion I will mention another instance, which still more seems to debilitate the validity of Giesbrecht's arrangement. On a closer investigation of the Calanoida from the Monaco Expedition instituted in the latter years, I have to my great astonishment found, that in the male of Bathycalanus Richardi G. O. Sars, a form unquestionably nearly allied to Megaca- lanus, the right anterior antenna is very distinctly hinged. According to this character the genus Bathycalanus should of course, if the primary division proposed by Giesbrecht is accepted, not only be wholly removed from the family Calanidce (in the restriction here adopted), but transferred to quite another section of the Calanoida, the Heterarthrandria, an arrangement which in reality would be absolutely unreasonable. 12 longest. Anterior antennae scarcely exceeding half the length of the cephalic segment and gradually tapering distally, being composed of 23 well-defined joints, the 1st of which is much the largest, occupying in length about l /3 of the antenna, and provided anteriorly, at some distance from the end, with a peculiar strongly developed spiniform appendages curving outwards and ter- minating in a thin filament; the succeeding joints very short and clothed anteriorly with small bristles; terminal joint longer than the preceding ones and narrow linear in form. Posterior antennae of an unusually compact structure, with the outer ramus much larger than the inner and 5-articulate, the first 2 joints considerably dilated. 1st pair of legs much smaller than the others, and having the basal part quite naked; both rami short, biartieulate, with the proximal joint small and unarmed, distal joint of outer ramus carrying 6, that of inner ramus 3 curved setae. The 4 succeeding pairs of essentially equal structure and very coarsely built, though somewhat diminishing in size posteri- orly; 2nd basal joint very large and obliquely truncated at the end, being provided outside near the end with a short spine, inside with a coarsely ciliated seta, which however is wanting on the last pair; both rami distinctly 3-articu- late in all the pairs and rather unequal, the outer one being much the larger; number of spines and setae slightly differing in the different pairs. Male somewhat smaller than female, but very like it in the general outward appearance, though perhaps . a little less robust. Anterior antennae with the number of joints somewhat reduced, being only 16-articulate, and moreover differing in the much fuller development of the aesthetasks, the number of which is about 8. Last pair of legs with the outer ramus slightly transformed, being only composed of 2 joints, the distal one rather elongated and somewhat constricted in the middle, with the inner edge quite smooth, the outer armed with 2 rather distant spines, end of the joint transversely truncated and carrying a thin partly ciliated lamella flanked by 2 unequal spines, the outer one of normal appearance, the inner long, styliform and quite smooth. Colour of the living animal not yet ascertained. Length of adult female reaching 0.95 mm., that of male 0.83 mm. Remarks. This interesting Calanoid was described and figured by the present author in the above-quoted Journal as the type of a new genus and even of a new family. It is now redescribed and new improved figures given. The resemblance, as to 'the outward appearance, to the species of the genus Pseudocyclopia is rather striking, and may be accounted for as the result of 13 a convergent evolution caused by the adaptation to similar conditions of life. It is undoubtedly, like the species of the said genus, a true bottom-form. Occurrence. Some few specimens of this remarkable form were picked up from a bottom sample taken several years ago at Korshavn from a depth of about 60 fathoms, coarse muddy sand. I have not met with it in any other place of the Norwegian coast. 7. Platycopia pygmasa, G. O. Sars, n. sp. (PI. VII, fig. 2). Specific Characters. Female. General form of body resembling that of the preceding species, though comparatively less robust. Anterior divi- sion considerably compressed and, viewed dorsally narrow oblong in out- line, with the greatest width scarcely exceeding Vs of the length. Urosome very narrow and nearly attaining half the length of the anterior division. Caudal rami much more elongated than in the type species, being more than 3 times as long as they are broad; seta of outer edge attached near the base of the ramus. Antennae, oral parts, and 1st pair of legs exhibiting a structure very similar to that in the type species. The 4 succeeding pairs of legs likewise built on the very same type, though differing in the inperfect segmentation of the inner ramus, its 2 outer joints being wholly coalesced in the 2nd pair and only slightly indicated in the 3 succeeding pairs. Male differing from the female in a very similar manner to that found in the preceding species. Anterior antennae, as in the male of P. perplexa, only composed of 16 joints, the outer 2 of which are rather elongated and narrow. Last pair of legs of a comparatively more compact structure than in the male of the preceding species, with both rami only composed of 2 joints, the outer one armed at the end of the broad, spatulate distal joint with 2 large, sabre-like spines, between which a thin hyaline lamella is attached. Colour of the living animal not yet ascertained. Length of adult female scarcely exceeding 0.60 mm. ; that of male 0.52 mm. Remarks. The present form is nearly allied to the type species, but evidently specifically distinct, differing not only in its much inferior size, but also in some of the structural details, as pointed out in the above given diagnosis. Occurrence. Only 3 specimens of this form, one female and 2 males, have as yet come under my notice. They were found in a bottom-sample likewise taken at Korshavn, but from somewhat shallower water, viz., about 30 fathoms, muddy bottom. 14 Fam. Pseudocyclopidae. Gen. Pseudocyclops, Brady. Remarks. Three species of this genus have as yet been recorded, one from the Mediterranean and 2 from the British coast. One of the latter, P. obtusalus Brady, is described in the 4th Volume of the present work, and I am now enabled to add to the fauna of Norway also the 2nd British species, to be described below. 8. Pseudocyclops crassiremis, Brady. (PI. VIII & IX). Pseudocyclops crassiremis, Brady, Nat. Hist. Trans. Northumberland and Durham, Vol. IV, p. 431, PI. XVII, figs. 18. Specific Characters. Female. Body rather robust, with the anterior division evenly vaulted above and somewhat compressed, seen dorsally, oblong oval in outline and nearly of equal width throughout. Cephalic segment very large, almost occupying half the length of the body, and obtusely rounded in front, exhibiting behind the middle a rather faintly marked transverse suture, inferior edges somewhat expanded in their anterior part. Rostrum very strong, deflexed, and acutely pointed at the tip. Last trunkal segment deeply emar- ginated behind in the middle and partly confluent with the preceding one, being only defined from it by a slight sinus of the inferior edges; lateral lobes broadly rounded at the end. Urosome not nearly attaining half the length of the anterior division; genital segment somewhat larger than the succeeding segment and slightly protuberant below; anal segment very small. Caudal rami scarcely longer than they are broad, and somewhat obliquely truncated at the end; apical setae of moderate length. Anterior antennas about half the length of the cephalic segment, and composed of 17 joints rather densely clothed with comparatively short curved setae; 1st joint much the largest and rather broad, carrying, in addition to the setae, 3 slender aesthetasks. Posterior antennae and oral parts of essentially same structure as in P. obtiisatus. Legs likewise rather similar; last pair, however, differing in the shorter and stouter form of the inner ramus, the joints of which, moreover, are almost wholly coalesced. Male somewhat smaller than female and easily recognisable by the more slender and distincly 5-articulate urosome. Rostrum, as in the male of P. obtusatus, sharply defined at the base, and somewhat smaller than in female. Right anterior antenna conspicuously hinged, with the middle joints rather tumefied, terminal movable part only composed of 3 joints, the 1st of which is produced at the end anteriorly to a slender spiniform process. Last pair of legs exceedingly strong and massive, being built on a similar type to that in the male P. obtusatus, though exhibiting some minor differences, as seen from the figure here given. Body in the living animal highly pellucid and nearly colourless; eye very conspicuous and of a light red colour. Length of adult female amounting to 0.86 mm., that of male to 0.80 mm. Remarks. This form was first described by Prof. Brady in the above quoted journal, and was subsequently briefly recorded by the same author in his well-known Monograph of British Copepoda. It is nearly allied to P. obtusatus, but of somewhat larger size and more robust form of body, differing moreover in some of the anatomical details, as pointed out in the above diagnosis. Occurrence. I have only met with this form in a single locality of the Norwegian coast, viz., at Korshavn, where some few specimens were taken from a depth of about 30 fathoms, muddy bottom. Distribution. British Isles (Brady). Fam. Acartiidae. Gen. Paracartia, Scott, 1894. Generic Characters. General appearance somewhat resembling that of Acartia; sexual differences, however, much more conspicuously marked. Last trunkal segment in both sexes wholly coalesced with the preceding segment, and in female expanded on each side to a broad wing-like lappet; in male simple, not expanded. Urosome in female short, and composed of only 3 segments, the 1st of which (the genital segment) is much the largest and lamellarly expanded laterally; caudal rami broad, with one of the apical seta converted to a strong spine. Urosome of male slender and composed of 4 well-defined segments, the 1st of which is rather small; none of the caudal 16 setae spiniform. Front in both sexes provided with 2 slender recurved filaments. Anterior antennae in female resembling in structure those in Acartia; right antenna in male conspicuously transformed and strongly hinged. Posterior antennas, oral parts, and natatory legs nearly as in Acartia. Last pair of legs in female comparatively large and confluent at the base, terminal joint claw- like; those in male powerfully developed and very asymmetrical; right leg much the larger and terminating in a slender incurved claw. Spermatophore affixed to the genital segment of the female, accompanied by a thin plate folding upwards on each side of the segment. Remarks. The name Paracartia was proposed in 1894 by Scott merely to designate a sub-genus of Acartia. I think, however, that the differences are greath enough to warrant this sub-genus to be raised to a true genus associated with Acartia in the family Acartiidce, as defined by the present author (see Vol. IV, p. 147). Scott records 2 supposed species of this genus, both found together in a plankton-sample taken in the bay of Guinea; but, as suggested by Giesbrecht, there can be no doubt that P, spinicaudata is the female and P. dubia the male of one and the same species, to which the latter name has been assigned by Giesbrecht. The Acartia laiisetosa of Kriczagin (= A. ver- rucosa Thompson) is apparently referable to the present genus, though differing in some particulars conspicuously from the species observed by Scott. On the other hand, is the Norwegian form described below very closely allied to that species. 9. Paracartia Grani, G. O. Sars. (PI. X & XI). Paracartia Grani, G. O. Sars, Bergens Museums Aarbog 1904, No. 4, p. 3, PI. I IV. Specific Characters. Female. Body comparatively slender, with the anterior division gradually narrowed in front. Wing-like expansions of last trunkal segment very large, triangular, each terminating in an acute point. Urosome scarcely exceeding in length J /4 of the anterior division, and some- what constricted in the middle; genital segment fully twice as broad as it is long, forming on each side a lamellar expansion obliquely truncated at the end. Caudal rami conspicuously asymmetrical, the right ramus being considerably broader than the left; marginal setae comparatively short, 2 of them attached to the outer edge; middle apical seta an both rami spiniform, that on right ramus much stronger than that on left. Anterior antennae not fully attaining the length of the anterior division of the body, and apparently composed of 17 or 18 joints, some of the proximal ones being however less distinctly defined. Last pair of legs comparatively strongly built, with the proximal parts completely coalesced in the middle, terminal parts claw-like and coarsely denticulated in their outer part, that on right side conspicuously larger than that on left side. Male of somewhat smaller size than female and very unlike it in its outward appearance. Anterion division regularly oblong oval in outline, with the last segment quite simple, without any lateral expansions. Urosome much more slender and narrow, cylindrical in form, with the 2nd segment the largest. Caudal rami comparatively small and quite symmetrical, marginal setae quite normally developed, none of them being spiniform. Right anterior antenna very strongly hinged and somewhat resembling in structure that in male Pontellidce; proximal part of the middle section considerably tumefied and composed of 4 firmly connected joints, distal part of that section formed by a single elongated and highly chitinised joint movably articulated both with the proximal part and with the succeeding terminal section; the latter com- posed of 4 joints, the 1st of which is the largest and armed in front with a long, dark-coloured claw-like spine. Last pair of legs powerfully developed and very asymmetrical, the right leg being more than twice as long as the left and exhibiting inside 2 differently shaped lappets, apical claw very slender and abruptly curved inwards; left- leg provided at the end with 2 peculiar appendages, the outer one somewhat lamellar and densely ciliated outside, the inner terminating in a styliform point. Colour of the living animal not yet ascertained. Length of adult female only slightly exceeding 1 mm.; that of male about the same. Remarks. This form has been fully described and figured by the present author in the above-quoted journal, and its close relationship to the tropical species recorded by Scott pointed out. Indeed, after having had the opportunity of examining some specimens of the latter species kindly sent to me from Scott, I am now much inclined to regard it as merely a somewhat depauperated form of that species left behind from a far remote period, in which a considerably warmer climate and a more southern fauna prevailed in our country. Occurrence. The present interesting form was found by Prof. H. Gran very abundantly in an oyster-bed (Espevigpollen) located at Tysnes, south of Bergen. It also occurred, though more sparingly, in another neighbouring bed (Sel0pollen). In both these beds the water holds during the summer a very high and uniform temperature amounting to no less than -(-30 C., and also 3 Crustacea. 18 in winter the temperature is comparatively high (up to -f- 10 C.). It is evident, that by this exceptional temperature, in connection perhaps with the chemical constitution of the water, quite particular conditions of life are created, which may have favoured the continued existence of the present southern form in the above mentioned isolated basins. Harpacticoida. Fam. Longipediidae. Gen. Sunaristes, Hesse. 10. Sunaristes paguri. Hesse. (PI. XII). See Vol. V, p. 15, PI. VI & VII. Specific Characters. Male. Body still more slender than in female, with no sharp demarcation between the two chief divisions, the posterior seg- ments of the trunk being scarcely wider than those of the urosome and of simple cylindrical form, without any distinct epimeral plates. Urosome com- posed of 5 well defined segments, the 1st of which (the genital segment) is only slightly larger than the succeeding one, and somewhat protuberant at the end below; last segment, as in the female, much smaller than the others. Caudal rami of same appearance as in the female. Anterior antennae very strongly built, and pronouncedly subcheliform, each terminating in a power- fully developed hand, with a well-marked projecting angle in front defining the palmar edge, against which the clawshaped terminal joint, or dactylus, admits of being impinged. Posterior antennas and oral parts exactly as in the female. Natatory legs likewise very similar, with the exeption of the 2nd pair, the inner ramus of which is conspicuously transformed, its 1st joint being produced at the end outside to a very strong mucroniform process extending beyond the middle of the terminal joint. Last pair of legs still more rudimentary than in female, all the setae arising immediately from the corresponding segment, without any intervening lamella. Genital lobes closely approximate and of obtusely triangular form, each carrying outside near the end a slender seta. Length of the specimen examined 2.15 mm. Remarks. Of this peculiar Copepod only the female sex was described in Vol. V. I now add the above short diagnosis of the male, and on PI. XII 20 give figures of the whole animal in dorsal and lateral aspects, and of some of the appendages more highly magnified. Occurrence. The male specimen here described was kindly sent to me from Dr. Jules Richard. I have myself not met with this Copepod since I observed the solitary female specimen described in Vol. V and taken at Hval0r, outside the Christiania Fjord. Farn. Cerviniidae. Gen. Cerviniopsis, G. O. Sars. 11. Cerviniopsis clavicornis, G. O. Sars. (PI. XIII, fig. 1). Cfr. Vol. V, p. 22, PI. XII, PI. XIII, fig. 1. Specific Characters. Male. General form of body closely resembling that of female. Rostral plate, however, comparatively larger and more pro- minent, and the 2 anterior caudal segment more sharply marked off from each other. Anterior antennae only slightly transformed, and scarcely at all prehen- sile, being apparently composed of 8 joints, the outer 4 of which, however, are less perfectly defined and together form a thinner terminal part bent back- wards at an angle to the proximal part; 2nd, 3rd, 4th and 6th joints each with a well-developed aesthetask; last joint very small and armed at the tip with a minute claw-like spine accompanied by some unequal setae. Posterior antennas, oral parts, and natatory legs exactly as in the female. Last pair of legs, however, conspicuously transformed, each leg being composed of 3 well- defined joints, the 1st of which, as in female, is quite short and produced outside to a digitiform process carrying a slender seta; middle joint armed at the end outside with a slender spine and about of same size as the terminal one, which carries 5 spines, one outside, 2 inside and 2 on the tip. Genital lobes rather remote, the one from the other, and of very small size, knob-like, each lobe carrying on the tip 2 slender setae. Length of the specimen examined 1.13 mm. Remarks. Ql this form also only the female sex has been described in Vol. V. The male, of which I now am enabled to give a diagnosis, is so very like the female in its outward appearance, that it easily may escape 21 attention. It is however of somewhat inferior size and moreover, on a closer examination, exhibits some well-marked sexual differences, especially as regards the structure of the anterior antennae and the last pair of legs. The imperfect prehensile nature of the former appendages is very remarkable. Occurrence. The present peculior Copepod was formerly only known from the Lofoten islands. I have in the latter years taken it rather abun- dantly at Ris0r, South coast of Norway, in depths ranging from 60 to 100 fathoms, muddy bottom. Among the numerous specimens collected only very few males were detected. Gen. Zosime, Boeck. Remarks. Two well defined species of this genus, Z. typica Boeck and Z. incrassata G. O. Sars, have been described in Vol. V. In the present Volume 2 other species are added, both of which are closely allied to the typital one, though apparently distinct. 12. Zosime major, G. O. Sars, n. sp. (PI. XIII, fig. 2). Specific Characters. Female. Very like Z. typica in its outward appearance, but of considerably larger size and comparatively more slender form of body. Anterior segments of urosome, as in that species, expanded laterally to triangular recurved lamellae finely spinulose at the edges; penultimate segment simple, cylindrical in form, and armed along the hind edge dorsally with a dense and regular row of rather coarse denticles. Caudal rami rather produced, being fully 3 times as long as they are broad, and somewhat con- stricted at the base; anterior half of the outer edge finely spinulose, seta of same edge of moderate size and attached near the end of the ramus; apical setae only 3 in number on each ramus, that usually attached to the outer corner being wholly absent; innermost seta comparatively small, the other 2 rather strong and clothed in their outer part with small prickles instead of the usual cilia. Antennae, oral parts, and natatory legs of a structure very similar to that in the type species. Last pair of legs, however, differing in the much larger size of the inner expansion of the proximal joint, which is broadly rounded at the end and provided with 4 strong marginal setae; distal joint comparatively small, but well defined at the base. Colour whitish grey. 22 Length of adult female amounting to 0.70 mm. Remarks. The present species is closely allied to the typical one, but of considerably larger size and somewhat more slender form of body, differing moreover conspicuously in the more produced caudal rami and in the structure of the last pair of legs. It is very probable, that the form recorded by British authors as Z. typica Boeck is more properly referable to the present species. Occurrence. I have met with this form occasionally in 2 different localities on the southern coast of Norway, viz., at Korshavn and Ris0r. It occurred in both places together with the typical species in depths ranging from 20 to 50 fathoms, muddy bottom. Only female specimens have as yet come under my notice. Distribution.? British Isles (Brady & Scott). 13. Zosime valida, G. O. Sars, n. sp. (PI. XIV). Specific Caracters. Female. Body of a more robust and compact form than in the preceding species, with the 2 chief divisions less sharply marked of from each other and nearly of equal length. Rostral plate rather prominent and sub-triangular in form, tip narrowly truncated and carrying the 2 usual sensory hairs. Lateral lobes of the anterior caudal segments far less prominent than in the preceding species; penultimate segment, as in that species, armed along the hind edge dorsally with a row of denticles, which however are much stronger and of a somewhat flattened form. Caudal rami comparatively broad, sub-lamellar, the greatest width considerably exceeding half the length; seta of outer edge remarkably strong and attached to a sharply defined ledge somewhat remote from the end; apical setae present in the usual number, that of the outer corner longer than that of the inner; the 2 middle setae well developed and of quite normal appearance. Anterior antennas apparently composed of 7 joints densely clothed with setae, most of which are coarsely ciliated. Posterior antennae, oral parts, and natatory legs exhibiting the structure characteristic of the genus. Last pair of legs with the distal joint wholly confluent with the proximal one; inner expansion of the latter com- paratively small, and only provided with 2 slender setaa, both issuing form the narrowly truncated tip. Colour whitish grey. Length of the specimen examined 0.70 mm. 23^ Remarks. This form also is closely allied to the type species, though easily distinguishable both from it and from the preceding species by the comparatively more compact form of the body, and more particularly by the structure of the caudal rami and of the last pair of legs. Occurrence. Only a solitary female specimen of this form has hitherto come under my notice. It was taken last summer at Hval0r, outside the Chri- stiania Fjord, from a depth of about 20 fathoms, muddy bottom. Fam. Ectinosomidae. Gen. Ectinosoma, Boeck. i Remarks. This genus seems to be exceedingly rich in species. To the 13 species described in Vol. V I am now enabled to add 8 more, the number of Norwegian species thus arising to no less than 21 in all. The determination of these species is, however, in some cases not easy on account of the rather uniform outward appearance of the body, and the anatomical examination is moreover rendered rather difficult by the glossy and tough integuments and by the smallness and fragility of some of the appendages. The most reliable distinguishing character is derived from the structure of the last pair of legs, which is perfectly constant and in nearly every case exhibits some peculiarity characteristic of the species. 14. Ectinosoma proximum, G. O. Sars, n. sp. (PI. XV, fig. 1). Specific Characters. Female. Very like E. neglectum G. O. Sars, as to the general form of the body, but of somewhat smaller size. Rostral plate slightly prominent and, as seen dorsally, obtusely truncated at the end. Uro- some somewhat shorter than the anterior division and gradually tapered behind; anal segment scarcely more than half as long as the preceding segment and deeply incised behind in the middle. Caudal rami somewhat divergent, and almost twice as long as they are broad at the base; apical setae of moderate length. Anterior antennae comparatively rather short and stout, being apparently only composed of 5 joints densely clothed with strong curved setae. Posterior antennae, oral parts, and natatory legs exhibiting a structure very similar to 24 that in E. neglectum. Last pair of legs, however, differing conspicuously in the shape of the distal joint, the outermost lobe of which is narrow digitiform and defined from the remaining part of the joint by a deep and narrow incision extending almost to the base of the joint; inner expansion of proximal joint comparatively shorter than in E. neglectum, extending scarcely beyond the middle of the distal one; marginal setae of both joints coarsely ciliated and rather unequal in length, that issuing from the middle lobe of the distal joint being the longest and extending about to the end of the genital segment. Colour of the living animal not yet ascertained. Length of adult female scarcely exceeding 1 mm. Remarks. The outward appearance of the present form looks so very like that of E. neglectum G. O. Sars, that at first I was inclined to regard it as merely an accidental variety of that species. Having however subsequently obtained several specimens of this form from widely distant localities, and in all of them found the very same characteristic structure of the last pair of legs, I am now of opinion that it more properly ought to be regarded as specific- ally distinct. Occurrence. I have found this form in 2 widely distant localities on the Norwegian coast, viz., at Bejan, outside the Trondhjem Fjord, and at Riser, in depths ranging from 20 to 50 fathoms. All the specimens obtained were of the female sex. 15. Ectinosoma angulifrons, G. O. Sars, n. sp. (PI. XV, fig. 2). Specific Characters. Female. Body comparatively slender, with the anterior division only slightly dilated. Rostral plate not much prominent and, as seen from above, terminating in an acute angle. Urosome much shorter than the anterior division and only slightly tapered behind; anal segment scarcely exceeding half the length of the preceding segment, and slightly incised behind in the middle. Caudal rami small, about as long as they are broad, and somewhat divergent; apical setae of moderate length. Anterior antennae resembling in structure those in the preceding species, though com- paratively a little more slender. 1st pair of legs with the inner ramus, as usual, much larger than the outer, which scarcely extends beyond the middle joint of the former. Last pair of legs resembling in structure those in E. pro- pinqvum Scott, the distal joint being subquadrangular in form and somewhat unequally trilobed at the end; inner expansion extending beyond the middle Phaennidae Copepoda Suppl. Volume PI. i fc - : ti / 7 irA_ v G. O. Sars, del. Xanthocalanus minor, Giesbrecht. Stephidae Copepoda Suppl. Volume PI. ii \ - i i 1 ' o T \ *'> *,--,! ' G. O. Sars, del. Stephos minor, Scott Stephidae Copepoda Suppl, Volume PI. in i ; : G. O. Sars, del. Parastephos pallidus, G. O. Sars Pseudocyclopiidaa Copepoda Suppl. Volume PI. IV a.'. , / / G. O. Sars, del. Pseudocyclopia Giesbrechti, Wlfend. Pseudocyclopiidae Copepoda Suppl. Volume PI. v //,* > : . ' ; : "I i- / ? G xv, 4- ^-0 ^' . . G. O. Sars, del. 1. Pseudocyclopia Giesbrechti, Wlfend. (continued) 2. Pseudocyclopia crassicornis, Scott Platycopiidae Copepoda Suppl. Volume PI. VI T . / I , * >. A V III.' t v y ', , . G. O. Sars, del. Platycopia perplexa, 6. O. Sars Platycopiidae Copepoda Suppl. Volume P VII // *$ "' G. O. Sars, del. 1. Platycopia perplexa, 6. O. Sars (continued) 2. Platycopia pygmaea, 6. O. Sars Pseudocyclopidae Copepoda Suppl. Volume PI. VIII V - A. . fi . - - . . i 6. O. Sars, del. Pseudocyclops crassiremis, Brady Pseudocyclopidas Copepoda Suppl. Volume PI. IX I G. O. Sars, del. Pseudocyclops crassiremis Brady, (continued) Acartiidae Copepoda Suppl. Volume PI. x G. O. Sars, del. Paracartia Grani, 6. O. Sars Acartiidae Copepoda Suppl. Volume PI. XI .->^- _ At, , . --. ; ' \ i < . I G. O. Sars, del. Paracariia Grani, G. O. Sars (continued) Longipediidae Copepoda Suppl. Volume PI. XII - - \\\ G. O. Sars, del. Sunaristes paguri, Hesse (male) Cerviniidae Copepoda Suppl. Volume PI. XIII ! ' \ G. O. Sars, del. 1. Cerviniopsis clavicornis, 6. O. Sars (male) 2. Zosime major, 6. O. Sars Cerviniidae Copepoda Suppl. Volume PI. XIV : - . 1 m i ' ' ,. . "*7 n \ \4 p\ G. O Sars, del. Zosime valida, 6. O. Sars Ectinosomidae Copepoda Suppl. Volume PI. xv t?. i , ' ,y .C. ^ G. O. Sars, del. 1. Ectinosoma proximum, 6. O. Sars 2. angulifrons, 6. O. Sars Ectinosomidae Copepoda Suppl. Volume PI. XVI I I L / G. O. Sars, dal 1. Ectinosoma tenerum, G. 0. Sars 2. clavatum, G. O. Sars AN ACCOUNT OF THE CRUSTACEA OF NOR WAY WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES BY G. O. SARS VOL. VII - COPEPODA SUPPLEMENT PARTS III & IV * HARPACTIGOIDA (continued) WITH 16 AUTOTYPIC PLATES BERGEN PUBLISHED BYTHE BERGEN MUSEUM SOLD BY ALB. CAMMERMEYERS'S FORLAG, CHRISTIANIA 192O 25 of the distal joint; marginal setae shorter than in the preceding species and rather unequal. Male much smaller than female, but exhibiting a very similar form of the body. Anterior antennas transformed in the usual manner, but highly distinguished by the presence of a largely developed aesthetask attached by a short chitinous stalk to the upper face of the greatly tumefied median joint, and extending backwards along the side of the cephalic segment until its very end. Last pair of legs, as usual, much reduced in size. Colour light yellowish. Length of adult female 0.88 mm.; that of male 0.72 mm. Remarks. This form is nearest allied to E. propinqvum Scott, but is of more slender form of body, and moreover at once distinguished by the very different shape of the rostral plate, which is far less prominent and not, as in that species, spoon-shaped, but distinctly angular in front. Occurrence. I have only met with this form in a single locality on the Norwegian coast, viz., at Riser, where several specimens, both males and females, were found in depths ranging from 30 to 60 fathoms, muddy sand. 16. Ectinosoma tenerum, G. O. Sars, n. sp. (PI. XVI, fig. 1). Specific Characters. Female. Body exceedingly slender and narrow, seen dorsally, almost linear in form. All the integuments very thin and pellucid. Rostral plate somewhat prominent and, seen dorsally, narrowly truncated in front, the tip being abruptly recurved. Urosome scarcely exceeding in length the exposed part of the trunk, and very slightly tapered behind; genital segment about the length of the 2 succeeding segments combined; anal segment, as usual, the smallest. Caudal rami very short, being scarcely as long as they are broad; apical setae of moderate length. Anterior antennae more slender than in the 2 preceding species and rapidly tapering distally, being composed of 6 well-defined joints, the 2nd of which is somewhat dilated in front. Anterior lip, as in most other species of the present genus, projecting below in an acute recurved process. Anterior maxillipeds unusally powerfully developed, with the 2nd basal joint very large and muscular; apical claws much elongated .and abruptly curved in their outer part, which is moreover finely denticulate inside. Posterior maxillipeds very slender and narrow. Natatory legs of the usual appearance. Last pair of legs resembling somewhat in shape those in E. angulifrons ; outermost lobe of the distal joint, however, far remote from 4. Crustacea. 26 the other 2, issuing close to the base of the joint; appendicular bristle attached immediately inside this lobe; inner expansion of proximal joint extending beyond the middle of the distal joint; marginal setae of these legs rather unequal, none of them however of any considerable length. Colour of the living animal not yet ascertained. Length of adult female amounting to 0.82 mm. Remarks. The present species exhihits some points of affinity both to E. angulifrons G. O. Sars and to E. Herdmani Scott, differing however from both in the still more slender form of the body and in the powerfully developed anterior maxillipeds. From E. Herdmani, which it resembles in the thin and pellucid integuments, it is moreover distinguished by the different form of the anterior lip and by the less strong and rather unequal marginal setae of the last pair of legs. Occurrence. Some specimens of this form, all of the female sex, were picked up from a bottom-sample taken at Korshavn from a depth of about 60 fathoms, coarse muddy sand. 17. Ectinosoma clavatum, G. O. Sars, n. sp. (PI. XVI, fig. 2). Specific Characters. Female. Body comparatively robust, subclavate in form, being conspicuously dilated in its anterior part and rapidly tapering behind. Rostral plate not much prominent and obtusely blunted at the end. Urosome considerably exceeding in length .the exposed part of the trunk; genital segment not attaining the length of the 2 succeeding segments com- bined; anal segment scarcely half the size of the preceding segment, and slightly incised behind in the middle. Caudal rami somewhat produced, being con- siderably longer than thy are broad at the base, and only slightly divergent, each ramus exhibiting dorsally a well-marked longitudinal keel; apical setae somewhat thickened in their proximal part and rather elongated. Anterior antennae comparatively short, though, as in the preceding species, composed of 6 well-defined joints. Anterior maxillipeds far less robust than in the pre- ceding species, exhibiting the structure usually met with in the species of the present genus. Last pair of legs comparatively large, with the distal joint oblong quadrangular in form and rather regularly trilobate at the end, middle lobe the most prominent; inner expansion of proximal joint extending al- most as far as the distal joint; marginal setae of these legs of rather unequal length, that issuing from the middle lobe of the distal joint being the longest 27 and extending beyond the genital segment; appendicular bristle attached close to the base of the joint and accompanied by a transverse row of smal spinules. Colour of preserved specimens dark corneous. Length of adult female 0.78 mm. Remarks. This is a well defined and easily recognisable species, being especially distinguished by the comparatively robust, sub-clavate form of the body, as also by the structure of the caudal rami and of the last pair of legs. Occurrence. Some few specimens of this form, all of the female sex, were picked up from samples taken at Ris0r from a depth of about 30 fathoms, muddy sand. A solitary specimen was also obtained at Korshavn from about the same depth. / 18. Ectinosoma compressum, G. O. Sars, n. sp. (PI. XVII, lig. 1). Specific Characters. Female. Body rather slender and conspicuously compressed, exhibiting in the dorsal aspect of the animal a very narrow, almost linear form. Cephalic segment scarcely exceeding in length the exposed part of the trunk, and conspicuously contracted in front; rostral plate somewhat prominent and, seen from above, narrowly truncated at the end. Urosome scarcely exceeding in length the exposed part of the trunk and somewhat tapered behind, being covered on the ventral face with small spikes; genital segment fully as long as the 2 succeeding segments combined; anal segment small and deeply incised behind in the middle. Caudal rami quite short, being scarcely longer than they are broad, and somewhat divergent; apical setae rather elongated. Anterior antennae comparatively slender and attenuated, being composed of 6 well-defined joints. Anterior maxillipeds rather power- fully developed, though somewhat less so than in E. tenerum. Natatory legs with the rami comparatively slender, the outer one in 1st pair extending a little beyond the middle joint of the inner. Last pair of legs closely contiguous in the middle, with the proximal joint rather large and lamellar; distal joint broadly rounded in form, with the 2 outer marginal setae very long and slender, the innermost one much shorter; appendicular bristle attached to a small digiti- forrn process issuing from the edge between the 2 outermost setae; inner expansion of proximal joint rather narrow, and extending considerably beyond the middle of the distal joint, its apical setae very unequal, the inner one much elongated, the outer scarcely Vs as long. Colour of the living animal not yet ascertained. 28 Length of adult female 0.75 mm. Remarks. The present species is allied to E. melaniceps Boeck, but of considerably larger size and more slender form. The pronounced compres- sion of the body is also very characteristic, and has indeed given rise to the specific name here proposed. Finally, well-marked differences are found in the structure of the anterior maxillipeds and of the last pair of legs. Occurrence. Some few specimens of this form, all of the female sex, were picked up from samples taken at Korshavn from a depth of about 60 fathoms, coarse muddy sand. 19. Ectinosoma tenuipes, Scott. (PI. XVII, fig. 2). Ectinosoma tenuipes, Scott, Revision of the British species belonging to the genera Bradya and Ectinosoma. Trans. Linn. Soc. of London. Vol. VI, Part 5, p. 436, PI. 36, figs. 25, 32, 35; PI. 37, figs. 9, 19, 30, 47; PI. 38, figs. 12, 17, 36, 52. Specific Characters. Female. Body considerably shorter and stouter than in the preceding species, with the anterior division somewhat dilated in the middle. Cephalic segment about the length of the exposed part of the trunk and gradually narrowed in front; rostral plate only slightly prominent and, seen from above, obtusely blunted at the tip. Urosome about equalling in length 2 /3 of the anterior division, and rapidly tapered behind; genital seg- ment not fully as long as the 2 succeeding segments combined; anal segment a little shorter than the preceding segment, and deeply incised behind in the middle. Caudal rami short, quadrangular, and slightly divergent; apical setae rather slender. Anterior antennae, as in the preceding species, 6-articulate, but somewhat less slender. Anterior maxillipeds less powerful, and of the usual appearance. Natatory legs with the rami comparatively slender and narrow, some of the apical spines and setae excessively elongated. Last pair of legs resembling in structure those in the preceding species, the distal joint exhibiting a similar broadly rounded form, though distinguished by the presence of a well-marked rounded prominence near the base inside, as also by the less elongated marginal -setae, the outermost of which is much shorter than the middle one; appendicular bristle, as in that species, attached to a narrow digitiform process issuing from the edge between the 2 outermost setae; inner expansion of proximal joint scarcely extending beyond the middle of the distal joint, its outer apical seta about half the length of the inner and not spiniform. Colour of the living animal not yet ascertained. Length of adult female scarcely exceeding 0.60 mm. 29 Remarks. This form, first described by Scott in the above-quoted treatise, is far inferior in size to those recorded in the preceding pages, and may moreover easily be recognised by its shorter and stouter body as also by the extraordinary length of some of the spines and setae attached to the nata- tory legs. The last pair of legs are built on the same type as in the preceding species and in E. melaniceps, though exhibiting some well-marked differences from both of them. Occurrence. I have met with this small species in 2 different localities of the south coast of Norway, viz., at Riser and Korshavn. It occurred occasio- nally in depths ranging from 20 to 100 fathoms. Distribution. Scottish coast (Scott). 20. Ectinosoma distinctum, G. O. Sars, n. sp. (PI. XVIII, fig. 1). Specific Characters. Female. General form of body somewhat re- sembling that in E. tenerum, thoug comparatively less slender, the anterior division being slightly dilated in the middle. Cephalic segment exceeding somewhat in length the exposed part of the trunk, and rapidly contracted in front; rostral plate rather prominent and, seen from above, obtusely pointed at the end. Urosome exceeding in length 2 /s of the anterior division, and only slightly tapered behind; genital segment about the length of the 2 suc- ceeding segments combined; anal segment, as usual, the smallest and only slightly incised behind in the middle. Caudal rami comparatively short, being scarcely longer than they are broad at the base; apical setae rather slender. Anterior antennae comparatively short and stout, though composed of 6 well- defined joints. Posterior antennae with the outer ramus well developed, extending as far as the inner. Anterior maxillipeds with the 2 basal joints of about equal size. Natatory legs built on the usual type, the outer ramus being in 1st pair much smaller than the inner and scarcely extending beyond its middle joint. Last pair of legs, however, exhibiting a rather characteristic structure; distal joint narrow quadrangular in form, with the 2 outermost marginal setae exceedingly strong and greatly thickened at the base, whereas the innermost seta is quite rudimentary; appendicular bristle rather fully developed and attached close to the base of the joint; inner expansion of proximal joint comparatively short and stout, not nearly extending to the middle of the distal joint, and coarsely ciliated inside, both apical setae strongly developed and of a similar 30 appearance to the 2 outermost setae of the distal joint. Ovisac comparatively small, with a very limited number of ova. Colour of the living animal not yet ascertained. Length of adult female 0.51 mm. Remarks. The present species is especially distinguished by the peculiar structure of the last pair of legs, which is unlike that in any other known species, though by the strong development of some of the marginal setae somewhat recalling that in E. gothiceps Giesbrecht. The rudimentary condition of the innermost seta in the distal joint is however very characteristic and quite peculiar to the present species. Occurrence. Two female specimens only of this form have as yet come under my notice. One of them was picked up from a sample taken at Korshavn from a depth of about 30 fathoms; the other specimen was found last summer at Hvaler, outside the Christiania Fjord. 21. Ectinosoma obtusum, G. O. Sars, n. sp. (PI. XVIII, fig. 2). Specific Characters. Female. Body comparatively short and stout, with the anterior division slightly dilated in the middle. Cephalic segment scarcely exceeding in length the 3 succeeding segments combined and, seen dorsally, obtusely rounded anteriorly, the rostral plate being abruptly deflexed and scarcely at all prominent in front. Urosome somewhat exceeding in length the exposed part of the trunk and gradually tapered behind. Caudal rami very short, scarcely as long as they are broad; apical setae of moderate length. Anterior antennae comparatively slender and attenuated, 7-articulate. Posterior antennae with the outer ramus less fully developed than in the preceding species, and not nearly extending as far as the inner. Anterior maxillipeds with the 2nd basal joint somewhat larger than the 1st. Natatory legs of the usual structure. Last pair of legs built on the same type as in E. melaniceps and allied species; distal joint comparatively broad and somewhat oblique, with a small tuberculiform prominence inside the middle, terminal edge irregularly lobular, and exhibiting, somewhat outside the middle, a deep incision separating the outermost lobe from the other 2, which are closely juxtaposed and occupy the most prominent part of the joint; marginal setae of moderate length and somewhat unequal, the innermost one being the shortest, but of rather coarse structure, almost spiniform ; appendicular bristle very small and attached to a well defined lobule issuing from the edge immediately inside the outermost 31 marginal seta; inner expansion of proximal joint rather narrow and extending about to the middle of the distal joint, outer apical seta comparatively short and stout, spiniform. Colour of the living animal not yet ascertained. Length of adult female 0.47 mm. Remarks. In its general appearance this form looks not unlike E. brevirostre G. O. Sars, from which species it may however at once be distin- guished by the much shorter caudal rami, and more particularly by the very different structure of the last pair of legs. It is also of rather inferior size. Occurrence. A solitary female specimen only of this form has as yet come under my notice. It was picked up from a sample taken at Korshavn from a depth of about 30 fathoms. Gen. Pseudobradya, G. O. Sars. Remarks. This genus was established in the year 1911 by the present author, to comprise some species referred by Scott to the genus Bradya of Boeck, but differing from that genus in several points, both as regards the outward appearance and the structure of some of the appendages. Seven species of this genus have beeri described in Vol. V of the present work, and I am now enabled to add no less than 10 species, all of them new to science. The total number of Norwegian species is thereby increased to 17 in all. 22. Pseudobradya digitata, G. O. Sars, n. sp. (PI. XIX). Specific Characters. Female. Body moderately slender, with the anterior division only slightly dilated in the middle. Cephalic segment much shorter than the exposed part of the trunk, equalling about in length the 3 succeeding segments combined; rostral plate short and somewhat deflexed, with the end obtusely rounded. Urosome attaining in length about 3 A of the anterior division and slightly tapered behind; genital segment, of moderate size; anal segment about half the length of the preceding segment and slightly incised behind in the middle. Caudal rami somewhat longer than they are broad at the base and only slightly divergent, apical setae not much elongated. Anterior antennae very short and stout, though apparently composed of 6 joints clothed with strong curved setae. Posterior antennae with the inner ramus rather strongly built, outer one extending almost as far as the inner, and distinctly 32 3-articulate. Oral parts, as in the other species of the present genus, rather feebly developed. Natatory legs with the rami moderately slender, the inner one in 1st pair somewhat longer than the outer, in the succeeding pairs of about same length, 1st joint of this ramus wanting the usual seta inside, but produced at the end to a sharp corner; 2nd joint of same ramus armed in the 2 middle pairs with a well-marked spine inside in addition to the seta. Last pair of legs largely developed, with the distal joint spatulate in form and divided at the end into 3 nearly equal, digitiform lobes separated by deep incisions and clothed with slender spinules, each lobe carrying a well developed seta, that of the middle lobe being, as usual, the longest and extending almost to the end of the 2nd caudal segment, innermost seta shorter than the other 2, but considerably coarser, almost spiniform; appendicular bristle well deweloped and attached near the base of the joint, being accompanied with a transverse row of small spinules; inner expansion of proximal joint scarcely extending to the middle of the distal joint and clothed with a number of small spinules, both apical setae rather slender and nearly equal. Colour of the living animal not yet ascertained. Length of adult female somewhat exceeding 1 mm. Remarks. In size and general appearance this form looks not unlike Ectinosoma neglectum G. O. Sars, and may at the first sight easily be con- founded with it. On a closer examination, however, it is found to be very different and unquestionably belonging to the present genus. It is the largest of the known species, and may moreover be recognised from any of them by the structure of the last pair of legs. Occurrence, Some few specimens of this handsome species were picked up from samples taken at Riser from a depth of about 50 fathoms, muddy sand. I have not met with it in any other place on our coast. 23. Pseudobradya leptognatha, G. O. Sars, n. sp. (PI. XX). Specific Characters. Female. Body rather slender, with the anterior division somewhat dilated in the middle. Cephalic segment fully as long as the exposed part of the trunk and rapidly narrowed in front; rostral plate com- paratively small and obtusely rounded at the end. Urosome about equalling in length Vi of the anterior division and rapidly tapered behind; genital seg- ment rather large, though not fully attaining the length of the 2 succeeding segments combined; anal segment comparatively small and minutely incised 33 behind in the middle. Caudal rami about twice as long as they are broad and not at all divergent, each having a well-marked keel along the dorsal faee; apical setae comparatively short. Anterior antennae very small, 5-articulate. Posterior antennae considerably more slender than in the preceding species, with the outer ramus scarcely half as long as the inner and only composed of 2 joints, the proximal one very small. Mandibles and maxillae of about same structure as in the preceding species. Anterior maxillipeds however rather different, being much reduced in size and simple cylindric in form, with none of the joints dilated. Posterior maxillipeds normally developed. Natatory legs comparatively more slender than in the preceding species, and not exhibiting any peculiarity in their structure. Last pair of legs comparatively large, with the distal joint oval in form, its terminal lobes far less sharply marked off from each other than in the preceding species and somewhat unequal, the outer- most one being placed rather in front of the other 2; marginal setae moderately slender, the innermost one the shortest and not spiniform; appendicular bristle well developed and attached at a short distance from the base of the joint; inner expansion of proximal joint rather narrow and extending somewhat beyond the middle of the distal joint, outer apical seta much shorter than the inner, which is attached somewhat more in front. Colour of the living animal not yet ascertained. Length of adult female, 0.78 mm. Remarks. The present form is especially distinguished by the peculiar rudimentary condition of the anterior maxillipeds, a character by which it differs from any of the other known species, and which indeed has given rise to the specific name here proposed. It also exhibits some other well- marked differences from the other species, as pointed out in the above diagnosis. Occurrence. A solitary female specimen only of this distinct species has hitherto come under my notice. It was found in a sample taken at Ris0r in the same place as the preceding species. 24. Pseudobradya scabriuscula, G. O. Sars, n. sp. (PI. XXI). Specific Characters. ^Female. Body moderately slender, with the anterior division- scarcely at all dilated in the middle. Cephalic segment slightly exceeding in length the exposed part of the trunk, and gradually narrowed in front; rostral plate somewhat prominent and obtusely pointed at the end. Urosome 5. Crustacea. 34 about equalling in length 3 A of the anterior division, and only slightly tapered behind, its segments successively diminishing in size and, like the trunkal segments, provided, in addition to the usual spinulation of the hind edge, with a trans- verse row of small spinules across the middle of the back. Caudal rami com- paratively short, scarcely longer than they are broad at the base; apical setae not much elongated. Anterior antennas very small, 6-articulate. Posterior antenna? with the outer ramus rather slender, extending almost as far as the inner, and 3-articulate, the first 2 joints very small. Oral parts of normal structure. Natatory legs comparatively slender, with the rami somewhat unequal in length; the inner one being in 1st pair longer than the outer, in the suc- ceeding pairs rather shorter; middle joint of this ramus in 3rd pair with 2 well-developed setae inside. Last pair of legs somewhat resembling in shape those in P. digitata, the distal joint being rather large and spatulate in form, though having the surface nearly smooth and the terminal lobes less sharply marked off from each other, innermost marginal seta very slender and longer than the other 2, which are nearly equal; appendicular bristle well developed and attached close to the base of the joint; inner expansion of proximal joint extending nearly to the middle of the distal joint, apical setae rather unequal, the outer one the shorter and spiniform. Colour of the living animal not yet ascertained. Length of adult female 0.75 mm. Remarks. The present species may be easily distinguished from the 2 preceding ones by the somewhat less slender form of the body and by the rather conspicuous spinulose armature of the segments, giving the body a somewhat scabrous appearance; hence the specific name here proposed. More- over some well-marked differences are found in the structure of some of the appendages, as pointed out in the above diagnosis. Occurrence. Two female specimens only of this form have as yet come under my notice. They were found in a sample taken at Riser in about the same place, where the 2^preceding species occurred. 25. Pseudobradya attenuata, G. O. Sars, n. sp. (PI. XXII). Specific Caraeters. Female. Body very slender, elongate subfusiform in shape, being conspicuously attenuated both in front and behind. Cephalic segment occupying about half the length of the anterior division and rapidly narrowed in front; rostral plate somewhat prominent and obtusely acuminate at the end. 35 Urosome exceeding somewhat in length 3 /4 of the anterior division and gradually tapered behind; genital segment much larger than the succeeding one; anal seg- ment about half the length of the preceding one and slightly indeed behind in the middle. Caudal rami a little longer than they are broad and not at all diver- gent; apical setae of moderate length. Anterior antennae remarkably short and stout, 5-artieulate, with the 2nd joint considerably dilated and divided anteri- orly into 2 sharply-defined setiferous lobes. Posterior antennae with the outer ramus rather small, not nearly attaining the length of the 1st joint of the inner, and biarticulate. Oral parts normal. Natatory legs moderately slender, inner ramus in 1st pair considerably longer than the outer, in the remaining pairs of about same length. Last pair of legs well developed, and somewhat resembling in structure those in P. leptognatha, the distal joint being oval in form, with the terminal lobes short and rather unequal, the outermost one placed far in front of the other two, marginal setae rather slender, the middle one the longest; appendieular bristle attached close to the base of the joint and accompanied by a transverse row of small spinules; inner expansion of proximal joint extending somewhat beyond the middle of the distal joint, apical setae very unequal, the outer one being scarcely half as long as the inner. Male, as usual, smaller than female and of still more slender form. Anterior antennae very distinctly hinged and composed of 6 well defined joints, the 4th of which is considerably tumefied and provided outside, at some distance from the base, with a large sausage-shaped aesthetask. Last pair of legs, as usual, much smaller than in female. Colour of the living animal not yet ascertained. Length of adult female 0.74 mm. Remarks. ^The above-described species is easily recognised by the slender subfusiform shape of the body in both sexes, and the unusually short and stout anterior antennae. Some differences from the preceding species are also found in the other structural details, as pointed out in the above diagnosis. Occurrence. Solitary specimens of this elegant species have been taken in 3 different places on the southern coast of Norway, viz., at Riser, Flekkere and Korshavn. It occurred in depths ranging from 20 to 60 fathoms. 26. Pseudobradya tenella, G. O. Sars, n. sp. (Pi.. XXIII, fig. 1). Specific Characters. Female. Body comparatively slender and narrow, subfusiform in shape, with rather thin and pellucid integuments. Cephalic segment considerably longer than the exposed part of the trunk and abruptly 36 contracted in front; rostral plate rather prominent and, seen from above, narrowly truncated at the end. Urosome about equalling in length 2 .'.; of the anterior division, and gradually tapered behind; genital segment much larger than the succeeding one; anal segment, as usual, the smallest and very slightly incised behind in the middle. Caudal rami comparatively short, being scarcely longer than they are broad; apical setae rather slender and elongated. Anterior antennae of moderate size and 6-articulate. Posterior antennae with the outer ramus nearly as long as the inner and biarticulate, 1st joint very small, distal joint somewhat curved and provided inside with a row of slender spinules. Oral parts and natatory legs of the usual structure. Last pair of legs com- paratively short, with the distal joint broadly quadrangular in form and having the terminal lobes densely spinulose and nearly equal, marginal setae unusu- ally short; appendicular bristle attached close to the base of the joint and accompanied inside by 4 small spinules; inner expansion of proximal joint extending almost as far as the distal joint, and provided across the middle with a row of delicate spinules, inner edge coarsely ciliated, apical setae, as usual, rather unequal in length. Colour of the living animal not yet ascertained. Length of adult female 0.63 mm. Remarks. This is a much smaller species than any of the 3 preceding * ones, and is moreover easily distinguished by the shape of the rostral plate and the structure of the last pair of legs. The specific name here proposed alludes to the very thin and pellucid integuments and the comparatively slender form of the body. Occurrence. Some few specimens of this form, all of the female sex, were picked up from samples taken partly at Riser, partly at Korshavn, the depth ranging from 20 to 60 fathoms. 27. Pseudobradya parvula, G. O. Sars, n. sp. (PI. XXIII, fig. 2). Specific Characters. Female. Body comparatively short and stout, with the anterior division'somewhat dilated in the middle. Cephalic segment occupying about half the length of that division, and abruptly contracted in Iront; rostral plate less prominent than in the preceding species and, seen from above, obtusely truncated at the end. Urosome only slightly exceeding in length the exposed part of the trunk and not much narrowed behind; genital segment, as usual, the largest and nearly equalling in lengt the 2 sue- 37 ceeding segments combined; anal segment shorter than any of the preceding ones, and broadly emarginated behind in the middle. Caudal rami compara- tively small, being scarcely longer than they are broad; apical seta rather slender. Anterior antennae comparatively shorter than in the preceding species, and only composed of 5 joints. Posterior antennae with the outer ramus somewhat shorter than the inner and very narrow, being composed of 3 joints, the first 2 very small. Anterior lip with a very conspicuous, almost rectangular protuberance in front. The other oral parts, as also the natatory legs, of normal structure. Last pair of legs comparatively small; distal joint narrow quadrangular in form and divided at the end into 3 well-defined and nearly equal lobes without any spinulose clothing, marginal setae rather slender and exhibiting the usual relation in length; appendicular bristle attached at some distance from the base of the joint and accompanied outside by a small spinule; inner expansion of proximal joint somewhat curved and not extending as far as the distal joint, apical setae, as usual, rather unequal in length. Colour of the living animal not yet ascertained. Length of adult female 0.56 mm. Remarks. This species is of still smaller size than the preceding one, from which it moreover at once is distinguished by the much shorter and stouter body. The shape of the anterior lip and that of the last pair of legs are also rather different. Occurrence. Some few specimens of this form, all of the female sex, were obtained from samples taken at Ris0r and Korshavn from depths ranging from 30 to 60 fathoms. 28. Pseudobradya pulchella, G. O. Sars, n. sp. (PI. XXIV, fig. 1). Specific Characters. Female. Body comparatively short, subfusilorm in shape, with the anterior division conspicuously dilated in the middle. Integu- ments rather firm and very glossy. Cephalic segment exceeding in length the exposed part of the trunk, and gradually narrowed in front; rostral plate not much prominent and, seen from above, obtusely rounded at the tip. Urosome slightly exceeding half the length of the anterior division and rapidly tapered behind; genital segment about the length of the 2 succeeding segments com- bined; anal segment small and narrowly incised behind in the middle. Caudal rami quadrangular in form, and scarcely longer than they are broad, each with a well-marked keel along the dorsal face; apical setae of moderate length. 38 Anterior antennae composed of 7 well defined joints, the 1st of which is much the largest, and exhibiting a very conspicuous patch of a dark pigment. Posterior antennae with the outer ramus comparatively small, scarcely exceeding in length the 1st joint of the inner, though composed of 3 well defined joints. Oral parts somewhat more fully developed than in most other species of the present genus. 1st pair of natatory legs with the spine attached outside the 2nd basal joint remarkably strong and quite smooth, inner ramus of this pair considerably larger than the outer. . Last pair of legs of moderate size; distal joint somewhat spatulate in form, with the terminal lobes well defined and nearly equal, inner edge of the joint distinctly ciliated; marginal setae moderately slender and exhibiting the usual relation in length ; appendicular bristle attached about in the middle of the joint and accompanied inside by 4 slender spinules; inner expansion of proximal joint comparatively short, not extending to the middle of the distal joint, and exhibiting at the base a transverse row of small spinules, inner edge distincly ciliated, apical setae rather unequal, the outer one scarcely exceeding half the length of the inner. Ovisac comparatively small. Colour of preserved specimens dark corneous. Length of adult female 0.55 mm. Remarks. The present species is easily recognised from those described in the preceding pages, and is especially distinguished by the dark corneous and glossy integuments and by the very conspicuous dark pigmentary patch on the base of the anterior antennae. In the latter respect it agrees with P. minor of Scott, which however otherwise is rather different. Occurrence. Two female specimens of this handsome species were picked up from a sample taken at Riser from a depth of about 40 fathoms. 29. Pseudobradya exilis, G. O. Sars, n. sp. (PI. XXIV, fig. 2). Specific Characters. Female. Body exceedingly slender and narrow, with the anterior division scarcely at all dilated in the middle. Cephalic seg- ment exceeding in length the exposed part of the trunk and rapidly tapered in front; rostral plate strongly prominent and acuminate at the end. Urosome slightly exceeding half the length of the anterior division and considerably tapered behind; genital segment fully as long as the 2 succeeding segments combined; anal segment very small and scarcely incised behind in the middle. Caudal rami short, about as long as they are broad, and rather approximate; apical setae very slender. Anterior antennae comparatively small, 6-articulate. Posterior antennae with the outer ramus unusually fully developed, exceeding considerably in length the inner, and composed of 3 well defined joints, the middle one the smallest, apieal spines rather elongated and coarsely spinulose at the one edge. Posterior maxillipeds of simpler structure than in the other species, being only eomposed of 2 joints, the distal one the longer and car- rying at the tip 2 unequal setae. The remaining oral parts apparently normal. Natatory legs powerfully developed, with the basal part thick and muscular, rami comparatively slender. Last pair of legs rather unlike in shape those in the other known species, the distal joint being considerably produced, with the outer part narrow sublinear in form and distinctly ciliated inside, outer- most lobe far remote from the other 2 and occurring near the base of the joint; marginal setae comparatively slender, the middle one being, as usual, the longest; appendicular bristle attached close to the base of the joint and accompanied by a transverse row of small spinules; inner expansion of proximal joint rather produced, extending beyond the middle of the distal joint and distinctly ciliated inside, apical setae slender and somewhat unequal in length. Colour of -the living animal not yet ascertained. Length of adult female 0.50 mm. Remarks. This is a very distinct and easily recognisable species, especially distinguished by the unusually large size of the outer ramus of the posterior antennae and the peculiar shape of the last pair of legs. The struc- ture of the posterior maxillipeds also is rather unlike that found in the other species of the present genus. Occurrence. A solitary female specimen only of this interesting species has as yet come under my notice. It was found in a sample taken, many years ago, at Bejan, outside the Trondhjem Fjord, from a depth of about 30 fathoms. 30. Pseudobradya pygmaea, G. 0. Sars, n. sp. (PI. XXIV, fig. 3). Specific Characters. Female. Body moderately slender and of the usual subfusiform shape. Cephalic segment about occupying Ira If the length of the anterior division and gradually tapered in front; rostral plate not much prominent and acute at the tip. Urosome about equalling in length '-/?, of the anterior division and rapidly tapered behind; genital segment comparatively large, equalling in length the 2 succeeding segments combined. Caudal rami scarcely longer than the anal segment; apical setae rather slender. Anterior antennae short and stout, 6-articulate. Posterior antennae with the outer ramus 40 comparatively small, scarcely longer than the 1st joint of the inner, and biarticulate. Oral parts and natatory legs of normal structure. Last pair of legs with the distal joint oval in form and quite smooth, terminal lobes some- what unequal, the outermost one being placed a little in front of the other 2, which are elosely juxtaposed, marginal setae rather slender and exhibiting the usual relation in length; appendicular bristle attached close to the base of the joint and not accompanied by any spinules; inner expansion of proximal joint extending a little beyond the middle of the distal joint and quite smooth inside, apical setae of the usual appearance. Ovisac comparatively small. Colour of the living animal not yet ascertained. Length of adult female 0.42 mm. Remarks. This is the smallest of the known species of the present genus and perhaps also of the whole family Ectinosomidce, and may thereby easily be recognized, though not exhibiting any more prominent peculiarity in its structure. Occurrence. Of this dwarfed species also only a solitary female specimen has hitherto come under my notice. It was found in a sample taken at Far- sund, south coast of Norway, from a depth of about 30 fathoms. 31. Pseudobradya ambigua, G. O. Sars, n. sp. (PI. XXV). Specific Characters. Female. Body of a rather robust appearance, with the anterior division not at all broader than the posterior and gradually attenuated anteriorly. Cephalic segment exceeding somewhat in length the exposed part of the trunk and greatly contracted in front, terminating in a strongly prominent rostral projection acuminate at the tip. Trunkal segments of about equal size, with the epimeral plates well developed and acutangular behind, each segment exhibiting a transverse row of small spinules in the middle of the back. Urosome unusually massive, equalling in length about ! /4 of the anterior division and, seen from above, only slightly narrowed behind, its segments successively diminishing in size and fringed behind with slender and delicate spinules; anal segment rather short and somewhat flattened, pro- jecting behind in the middle into 2 juxtaposed acuminate lappets. Caudal rami very short, being considerably broader than they are long; apical setae not much elongated, but rather strong. Anterior antennse very small, 5-articu- late. Posterior antennae with the inner ramus normally developed; outer ramus comparatively small, 3-articulate, and, as in most other species, very narrow linear in form, being however not, as usual, attached to the posterior distal corner of the basal part, but to a quadrangular piece firmely connected with the anterior corner and armed below with 2 strong, coarsely spinulose setae curving downwards in front of the inner ramus. Oral parts very small and scarcely extending beyond the edges of the epimeral plates, being however apparently built on the type characteristic of the present genus. Posterior maxillipeds distinctly 3-articulate, with the middle joint comparatively broad, sub-lamellar, and densely spinulose inside, last joint provided with 4 some- what unequal setae. Natatory legs well developed, with the basal part com- paratively broad and muscular, rami rather slender, the inner one being in 1st pair somewhat longer than the outer, in the remaining pairs of about same length. Last pair of legs broad, foliaceous, and closely contiguous along the middle; distal joint oval in form, with the terminal lobes somewhat unequal, the outermost one occurring rather in front of the other 2; marginal setae very strong and coarsely ciliated, the 2 outermost ones distinctly defined at the base, whereas the innermost one forms the immediate continuation of the joint; appendicular bristle well developed and attached near the base of the joint; inner expansion of proximal joint quite short, but rather broad, with both setse remarkably strong and not defined by any suture at the base. Male nearly of same size as female and very like it in its outward appearance, though having the urosome, as usual, distinctly 5-articulate. Anterior antennae much larger than in female, and distinctly hinged, with the 3rd joint considerably enlarged and provided outside, at some distance from the base, with a large sausage-shaped eesthetask extending backwards along the side of the cephalic segment. 2nd pair of legs with the inner ramus slightly transformed, being comparatively longer than in female, with the terminal joint narrowly produced and quite smooth on both edges, tip car- rying a short, somewhat flexuous spine and a slender seta. Last pair of legs much smaller than in female, with the marginale setae shorter and all of them distinctly defined at the base. Colour of the living animal not yet ascertained. Length of adult female 0.82 mm. Remarks. This is a rather anomalous species, distinguished both by the peculiar outward appearance of the body and by the structure of some of the appendages. Especially is the structure of the posterior antennae very peculiar and unlike that found in any of the other known species. Occurrence. 3 specimens of this remarkable form, 2 females and 1 male, have been examined by me. One of the female specimens was taken, 6 Crustacea. 42 many years ago, at Selven, Trondhjein Fjord, from a depth of about 7 fathoms; the other 2 were picked up from a sample taken at Korshavn, south coast of Norway, from a considerably greater depth, viz., 50 fathoms. Gen. Bradya, Boeck. Remarks. In the restriction here adopted, only 3 species of this genus have hitherto been recorded, viz., B. typlca Boeck, B. dilatata G. O. Sars, and B. armigera (Scott). I am now enabled to add 5 new species, to be described in the sequel, increasing the number of Norwegian species to 8 in all. 32. Bradya Scotti, G. O. Sars, n. sp. (PI. XXVI). Specific Characters. Female. Body resembling in shape that of B. typica, though comparatively somewhat more robust, with the anterior division more tumid. Cephalic segment equalling about in length the exposed part of the trunk, and only slightly contracted in front; rostral plate somewhat deflexed and, seen from above, obtusely rounded at the end. Epimeral plates of the 3 succeeding segments well developed and acutangular behind. Last trunkal segment comparatively small and without any distinct epimeral plates. Urosome considerably narrower than the anterior division and exceeding some- what half its length ; genital segment about equalling in length the 2 succeeding segments combined; anal segment much the smallest and only slightly incised behind in the middle. Caudal rami about the length of the anal segment and somewhat divergent; apical setae moderately slender. Antennae, oral parts, and natatory legs of a structure very similar to that in B. typica. Last pair of legs, however, exhibiting some well-marked differences; distal joint compa- ratively larger and more regularly quadrangular in form, with the innermost marginal seta considerably shorter than the middle one; appendieular bristle well developed and attached at some distance from the base of the joint; inner expansion of proximal joint comparatively narrower than in B. typica, with the apical setae very unequal, the inner one much stronger than the outer and nearly 3 times as long. Colour of the living animal not yet ascertained. Length of adult female 0.88 mm. 43 Remarks. The present species is closely allied to B. typica and about of same size, but of somewhat more robust form of the body, and more parti- cularly distinguished by the shape of the last pair of legs and the rather different mutual relation of the setae attached to the distal joint of that pair. According to the figures of these legs given by Brady and Scott, it would seem that the British form recorded as B. typica Boeck is more properly referable to the present species. Occurrence. Specimens of this form have been obtained at Ris0r together with the typical species, and it is very probable that on a closer investigation it also will be found to occur in many other places on the Norwegian coast. 33. Bradya macrochaeta, G. O. Sars, n. sp. (PI. XXVII, fig. 1). Specific Characters. Female. Body exhibiting the usual somewhat obpyriform shape, the anterior division being considerably broader than the posterior, with the greatest width somewhat in front of the middle. Cephalic segment comparatively large, exceeding in length the exposed part of the trunk, and only slightly contracted in front; rostral plate strongly deflexed. Epimeral plates of the 3 succeeding segments bluntly angular behind. Uro- some but little exceeding half the length of the anterior division, and gradu- ally tapered behind; genital segment fully as large as the 2 succeeding seg- ments combined; anal segment, as usual, the smallest and slightly incised behind in the middle. Caudal rami about the length of the anal segment and somewhat divergent; apical setae very slender. Antennae, oral parts, and natatory legs of quite normal structure. Last pair of legs, however, distinguished by the excessive length of the marginal setae, some of them extending almost to the end of the tail; distal joint of those legs comparatively small, with the middle seta the longest; inner expansion of proximal joint not much produced, but with the apical setae very slender and elongated, the inner one nearly attaining the length of the middle seta of the distal joint. Colour pale whitish grey. Length of adult female 0.60 mm. Remarks. The present species is of much smaller size than the pre- ceding one, and may moreover at once be distinguished both from this and the other known species by the excessive length of the setae clothing the last pair of legs, a character which indeed has given rise to the specific name here proposed. 44 Occurrence. Some few specimens of this form, all of the female sex, were obtained some years ago at Ris0r in depths ranging from 50 to 100 fathoms, muddy bottom. 34. Bradya furcaia, G. O. Sars, n. sp. (PI. XXVII, fig. 2). Specific Characters. Female. Body comparatively short and stout, with the anterior division regularly elliptical in outline, the greatest width occurring about in the middle. Cephalic segment about the length of the exposed part of the trunk, and conspicuously contracted in its anterior part, with the extremity, seen from above, narrowly truncated; rostral plate rather deflexed. Urosome much narrower than the anterior division and about equalling 2 /s of its length, tapering rapidly behind, posterior edges of the segments distinctly spinulose. Caudal rarni unusually produced, attaining the length of the last 2 segments combined, and rather divergent; apical setae moderately slender. Anterior antennas short and stout, 6-articulate. Posterior antennae and oral parts normal. Natatory legs with the rami rather unequal, the inner one being much the longer, middle joint of this ramus fully as large as the terminal one, and in the 2nd pair armed inside with a strong spine in addition to the usual seta. Last pair of legs somewhat unlike those in the other species, the distal joint being comparatively large and rounded oval in form, with both the innermost and outermost setae very short; inner expansion of proximal joint extending beyond the middle of the distal joint, and having the 2 apical setae of nearly equal length. Body rather pellucid and of a whitish grey colour. Length of adult female 0.64 mm. Remarks. This is a well defined species, and may at once be recog- nised by the unusually long and narrow caudal rami, a character which indeed has given rise to the specific name here proposed. It also exhibits some well- marked differences from the other species in the structural details, especially as regards the structure of the last pair of legs. Occurrence. Two female specimens only of this form have as yet come under my notice. They were taken at Riser from a depth of about 60 fathoms. 45 35. Bradya congenera, G. O. Sars, n. sp. (PI. XXVIII, fig. 1). Specific Characters. Female. Body of the usual obpyriform shape, the anterior division being somewhat broader in front than behind. Cephalic segment about the length of the exposed part of the trunk, and slightly con- tracted at the anterior extremity, with the front, seen from above, obtusely truncated; rostral plate rather deflexed. Urosome somewhat exceeding half the length of the anterior division, and gradually tapered behind; genital segment fully as long as the 2 succeeding segments combined; anal segment, as usual, the smallest, though not much shorter than the preceding segment, and broadly emarginated behind in the middle. Caudal rami comparatively short, not nearly attaining the length of the anal segment and somewhat divergent; apical setae very slender. Anterior antennae of moderate size and composed of 8 well defined joints. Posterior antennae, oral parts, and natatory legs resembling in structure those parts in B. typica. Last pair of legs likewise very similar, the mutual relation in length of the setee attached to the distal joint being the very same. Ovisac comparatively small. Body of the usual whitish grey colour. Length of adult female scarcely exceeding 0.67 mm. Remarks. The present form is closely allied to B. typica, exhibiting a very similar structure of the several appendages. It is however of much smaller size, and may, on a closer examination, be distinguished by the comparatively shorter caudal rami and the distinctly 8-articulate anterior antennae. Occurren ce. Several specimens of this form have been collected at Riser together with the other species, and it probably also occurs in many other places of the Norwegian coast. As however its specific difference from B. typica has not formerly been recognised, the exact localities cannot at present be stated. 36. Bradya simulans, G. O. Sars, n. sp. (PI. XXVIII, fig. 2). Specific Characters. Female. Body resembling in shape that of B. furcata, being rather short and stout, with the anterior division elliptical in outline. Cephalic segment comparatively large, exceeding somewhat in length the exposed part of the trunk, and gradually contracted anteriorly, with the front, seen from above, narrowly rounded; rostral plate small, deflexed. Urosome about equalling in length 2 , 3 of the anterior division and rapidly 46 tapered behind; genital segment, as usual, much the largest; anal segment deeply incised behind in the middle. Caudal rami somewhat produced, exceeding in length the anal segment, and rather divergent; apical setae moder- ately slender. Anterior antennae comparatively smaller than in the preceding species and only composed of 6 joints. Posterior antennae, oral parts, and natatory legs exhibiting the usual structure. Last pair of legs likewise quite normally developed; distal joint of moderate size and quadrangular in form, with the marginal setae rather unequal, the middle one being much the longest, the outermost the smallest; inner expansion of proximal joint not much pro- duced, and having the apical setae moderatelyj slender and rather unequal. Ovisac comparatively small. Colour whitish grey. Length of adult female 0.61 mm. Remarks. The present species exhibits in the general shape of the body a perplexing resemblance to B. furcata, and may at the first sight easily be confounded with that species 1 On a closer examination, it is however found to differ in the somewhat less produced caudal rami, as also in the structure of some of the appendages, especially that of the last pair of legs. Occurrence. One or two specimens only of this form have as yet come under my notice. They were taken at Ris0r in a depth of about 60 fathoms, muddy sand. Gen. Halophytophilus, A. Brian, 1918. Generic Characters. Body somewhat resembling in its general shape that in the genus Bradya, though having the two chief divisions less sharply marked off from each other. Cephalich segment produced in front to a strongly chitinised recurved rostrum. Urosome very slender and attenuated. Anterior antennae comparatively strong, 6-articulate, with the terminal joint unusually prolonged. Posterior antennae with the outer ramus very small, inner one well developed, with the distal joint coarsely spinous. Mandibles with the masticatory part narrowly exserted, palp comparatively large, though having the rami short and stout. Maxillae not examined. Anterior maxillipeds with the 2nd basal joint remarkably long and narrow, forming with the 1st a sharp genicular bend. Posterior maxillipeds apparently 4-articulate, with the penulti- mate joint rounded and fringed with ciliated setae, terminal joint armed at the tip with claw-shaped spines. 1st pair of legs with the inner ramus sub-pre- 47 hensile and only composed of 2 unequal joints; rami of the succeeding 3 pairs normal. Last pair of legs comparatively large, foliaceous, resembling in structure those in the genus Pseudobradya. Remarks. This genus has been recently established by Dr. A. Brian, to include a small Ectinosomid found by him among marine littoral algae growing near the zoological laboratory of "Quarto dei Mille", Ligurian coast. As observed by that author, the most essential distinguishing character of this genus is derived from the structure of the 1st pair of legs, the inner ramus of which is peculiarly transformed and very unlike that found in any other form of the Ectinosomidae, being only composed of 2 joints and apparently prehensile in character. Otherwise the genus seems to approach that of Pseudobradya. A well-marked Norwegian species of this interesting genus will be described below. 37. Halophytophilus spinicornis, G. O. Sars, n. sp. (PI. XXIX). Specific Characters. Female. Body rather slender, broadest in front and gradually attenuated behind, with no sharp demarcation between the anterior and posterior divisions. Cephalic segment not fully attaining the length of the exposed part of the trunk and, seen from above, obtusely rounded in front; rostrum very coarse, acuminate, and curved downwards. The 3 suc- ceeding segments each with a transverse row of small spinules across the middle of the back, epimeral plates well developed and obtusangular behind. Last trunkal segment only slightly smaller than the preceding one. Urosome somewhat exceeding in length 2 /s of the anterior division, and rapidly tapered behind; genital segment rather large, though not fully attaining the length of the 2 succeeding segments combined; anal segment very small and only slightly incised behind in the middle. Caudal rami about the length of the anal seg- ment and not at all divergent, each with a well-marked keel along the dorsal face; apical setae very slender. Anterior antennae of moderate size and com- posed of 6 well defined joints rapidly diminishing in width distally and clothed with strong curved setae; 2nd joint armed, in addition to the setae, at the end with a very strong thickish spine; last joint very narrow and about the length of the 2 preceding joints combined. Posterior antennae very strongly built, with the terminal part (inner ramus) scarcely longer than the basal part, its distal joint armed along the anterior edge with 4 coarse thickish spines, apical setae 5 in number; outer ramus small, biarticulate with 2 slender setae at the 48 tip. 1st pair of legs with the outer ramus normally developed, inner ramus of about equal length, but very different in structure, being only composed of 2 joints, the proximal one much the larger and somewhat lamellar, with a very long deflexed seta inside near the end; distal joint about half the length of the proximal one and much narrower, carrying at the tip a slender some- what claw-like spine accompanied inside by 2 elongated setae, inner edge provided, at some distance from the end, with a much shorter seta. The 3 succeeding pairs with both rami 3-artieulate and sub-equal in length. Last pair of legs comparatively large, with the distal joint rather regularly oval in form and nearly smooth, terminal lobes well defined and slightly unequal; marginal setae moderately slender and exhibiting the usual relation in length; appendicular bristle well developed, and attached at some distance from the base of the joint, being accompanied outside by a single small spinule; inner expansion of proximal joint rather narrow, and extending about to the middle of the distal joint; apical setae slender and somewhat unequal in length. Colour of the living animal not yet ascertained. Length of adult female 0.67 mm. Remarks. The above-described form is evidently referable to the genus Halophytophilus 1 ) of Brian, exhibiting a quite analogous structure of the 1st pair of legs. It is however quite certainly specifically different from the typical form, H. fusifonnis Brian, being of much larger size, and moreover differing in the very conspicuous spinous armature of both antennae, as also in the relative length of the 2 joints composing the inner ramus of fhe 1st pair of legs, and in the number of setae attached to the distal joint of that ramus. Occurrence, A solitary female specimen only of this anomalous form has as yet come under my notice. It was found in a sample taken last summer at Hval0r, outside the Christiania Fjord, from a depth of about 10 fathoms, muddy bottom^ ') The aspiration of the first component of the name ((.^) has erroneously been omitted by thai author (Alophytopliilus), 49 Fam. Harpacticidae. Gen. Harpacticus, M. Edwards. 38. Harpacticus tenellus, G. O. Sars, n. sp. (PI. XXX). Specific Characters. Female. Body resembling in shape that of H. gracilis Glaus, but of somewhat smaller size and more delicate structure, with rather thin and pellucid integuments. Anterior division slightly depressed and oblong oval in outline, being rather sharply marked off from the com- paratively small urosome. Cephalic segment about the length of the trunk and evenly contracted in front; rostral plate somewhat prominent and obtusely rounded at the tip. Urosome not nearly attaining half the length of the anterior division and much narrower; genital segment comparatively large, occupying about half the length of the urosome. Caudal rami short, quadran- gular, scarcely as long as they are broad; apical setae much elongated. An- terior antennae very slender, attaining almost the length of the cephalic segment, and composed of 9 joints, the 3rd and 4th of which are rather narrow and elongated, subequal in size; terminal part, composed of the 5 outermost joints, scarcely longer than the preceding (4th) joint. Posterior antennae resembling those in H. gracilis, but of a more delicate structure. Posterior maxillipeds with the basal part much elongated and narrowed distally, hand less dilated than in the said species, being about twice as long as it is broad and somewhat curved, palmar edge well defined and armed, at some distance from the end, with a very conspicuous spiniform process curving upwards along the edge. 1st pair of legs built on the same type as in H. gracilis, but of more delicate structure, with the rami comparatively narrower, the inner one about the length of the 1st joint of the outer. Natatory legs of the usual structure. Last pair of legs with the distal joint oblong oval in form and comparatively narrower than in H. gracilis; inner expansion of proximal joint less produced. Ovisac large, rounded oval in form. Male fully as large as female and exhibiting the usual rather strongly marked sexual differences. Anterior antennae conspicuously hinged, though far less robust than in H. gracilis. Posterior maxillipeds scarcely more powerfull than in female. 2nd and 3rd pairs of legs transformed in a much similar manner to that in H. gracilis. Last pair of legs much reduced in size, with the proximal joint very small and not at all expanded inside : 7 Crustacea,. 50 Body in both sexes rather pellucid, of an uniform whitish grey colour, without any obvious pigment. Length of adult female 0.63 mm. Remarks. The present species is closely allied to H. gracilis Glaus, but of somewhat smaller size, and on the whole of a rather more delicate appearance. On a closer examination some well-marked differences are also found in the structural details, as pointed out in the above diagnosis. Occurrence. I have met with this species in several places both on the west and south coasts of Norway, but have formerly not been aware of its specific difference from H. gracilis Glaus. It is only found in depths ranging from 20 to 60 fathoms, never, as is the case with H. gracilis and most other species of the present genus, in the littoral zone. Fam. Idyaeidae. Gen. Idyaea, Philippi (Idya). 39. Idyaea graciloides, G. O. Sars, n. sp. (PI. XXXI). Specific Characters. Female. Body comparatively slender, resembling somewhat in shape that of /. gracilis Scott. Cephalic segment about equalling in length the 3 succeeding segments combined and rather broad behind; rostral prominence very small. Epimeral plates of the 3 succeding segments laterally expanded and closely contiguous. Last trunkal segment, as usual, very small and without any distinct epimeral plates. Urosome about equalling in length 2 /3 of the anterior division and much narrower; genital segment fully as long as the 3 succeeding segments combined and somewhat fusiform in outline, being conspicuously dilated in the middle. Caudal rami about as long as they are broad, and sub-quadrangular in form ; apical setae very slender, the outer- most and innermost ones rather thin and considerably longer than in /. gracilis. Anterior antennae slender and elongated, exceeding somewhat in length the cephalic segment, 3rd joint longer and narrower than the 2nd and about twice the length of the 4th; terminal part, composed of the 4 outermost joints, occupying about V-i of the length of the antenna. Posterior antenna; and oral parts of the usual structure. 1st pair of legs resembling somewhat those in 51 /. gracilis, the distal joint of the inner ramus being very narrow, though less elongated than in that species, only slightly exceeding in length the proximal joint. The 3 succeeding pairs of legs of quite normal appearance. Last pair of legs much smaller than in /. gracilis, with the distal joint rather narrow, sub-linear in form, and less densely hairy, all the setae issuing from the outer- most part of the joint. Male of nearly same size as female, but comparatively still more slender, with the urosome distinctly 5-articulate. Anterior antennae only slightly transformed, being a little thicker than in female, with a small joint intercalated between the 3rd and 4th; hinge rather imperfect. 2nd pair of legs with none of the setae transformed. Last pair of legs much reduced in size. Colour of the living animal not yet ascertained. Length of adult female 0.86 mm. Remarks. This form is nearest allied to /. gracilis Scott, but is evidently specifically distinct, differing in the comparatively less produced caudal rami, as also rather conspicuously in the structure of the anterior antennae and the last pair of legs. Occurrence. Several specimens of this form were picked up from samples taken at Korshavn from a depth of about 60 fathoms, muddy sand. I have not met with it in other places on the Norwegian coast. 40. Idyaea compacta, G. O. Sars, n. sp. (PI. XXXII). Specific Characters. Female. Body unusually short and compact, with the anterior division rather broad and somewhat depressed. Cephalic segment considerably exceeding in length the exposed part of the trunk, and only very slightly contracted in front. Epimeral plates of the 3 succeeding segments con- siderably expanded laterally and closely contiguous, sub-imbricate. Last trunkal segment, as usual, much narrower than the preceding ones, and without any epimeral plates. Urosome unusually short, only sligtly exceeding in length Va of the anterior division, its segments scarcely at all spinulose at the lateral corners, and densely crowded. Anal opercle rather prominent, semilunar, and coarsely denticulated at the edge. Caudal rami scarcely as long as they are broad at the base, and somewhat obliquely truncated at the end, the outer corner being the more prominent; apical setae very slender and elongated, the innermost but one almost attaining the length of the whole body; innermost and outer- most setae much thinner than the 2 middle ones and rather prolonged; seta 52 of outer edge apparently wanting. Anterior antennas comparatively short and stout, not nearly attaining the length of the cephalic segment, and gradually attenuated distally; 2nd joint much the largest, 4th joint about half the length of the 3rd; terminal part somewhat shorter than the 2 preceding joints com- bined. Posterior antennae and oral parts of quite normal appearance. 1st pair of legs resembling somewhat in structure those in /. furcata; 2nd joint of inner ramus however comparatively shorter, not attaining the length of the 1st; apical claws of this ramus considerably longer than in I. furcata. Natatory legs of the usual structure. Last pair of legs of moderate size, with the distal joint oblong oval in form and comparatively broader than in /. furcata, edges of the joint only provided with a few scattered small spinules, apical setae rather slender. Colour of the living animal not yet ascertained. Length of adult female 0.62 mm. Remarks. The above-described form may be easily recognised by its wery short and compact body, and more particularly by the unusually poor development of the urosome. It belongs to the smaller species of the pre- sent genus. Occurrence. Two female specimens only of this form have as yet come under my notice. They were found in a sample taken, some years ago, at Riser from a depth of about 50 fathoms. Gen. Idyella, G. O. Sars. 41. Idyella major, G. O. Sars, n. sp. (PI. XXXIII, fig. 1). Specific Characters. Female. Body rather short and stout, with the anterior division considerably dilated and somewhat vaulted dorsally. Cephalic segment very large, about as long as it is broad, and evenly rounded in front; rostral projection small and recurved. The 3 succeeding segments successively diminishing in width, and having the epimeral plates not much prominent laterally. Last trunkal segment very small. Urosome not nearly attaining half the length of the anterior division and much narrowed; genital segment com- paratively large, occupying half the length of the urosome, and forming on each side a broad lamellar expansion angular behind. Caudal rami very small, quadrangular, with the apical setae rather slender and scarcely at all divergent, Ectinosomidae Copepoda Suppl. Volume PI. XVII ; : "i~* {>. "S tfijt >1 i nM i " i\ i ; ; //M y i ' ' ,' ' - G. O. Sars, del. 1. Ectinosoma compressum, 6. O. Sars 2. tenuipes, Scott Ectinosomidae Copepoda Suppl. Volume PI. XVIII c -' 6. O. Sars, del. 1. Ectinosoma distinctum, 6. O. Sars 2. obtusum, 6. 0. Sars Ectinosomidae Copepoda Suppl. Volume PI. XIX . /^' > : \ i ^ j ', i: \[\ ' \ . 1 - ! j ' - ' . * ,-\ G. O. Sars, del. Pseudobradya digitata. 6. 0. Sars Ectinosomidae Copepoda Suppl. Volume PI. XX *' o -.. i G. O. Sars, del. Pseudobradya leptognatha, 6. 0. Sars Ectinosomidae Copepoda Suppl. Volume PI. XXI V / //. i G. O. Sars, del. Pseudobradya scabriuscula, G- 0. Sars Ectinosomidae Copepoda Suppl. Volume PI. XXII ' '1 ' i . I . \ 1 ' ' f) 'i cZ- G. O. Sars, del. Pseudobradya aitenuata, 6. O. Sars Ectinosomidas Copepoda Suppl. Volume PI. XXIII - . \ /^ \ r,4KWva v '' ; /'a '' ' ! \ *X !% I f % , N rx l| 'i j \ . -i/ 1 ( *j > - \ ._>^ f/'M/^? o.So. : m . n n G. O. Sars, del. 1. Pseudobradya pulchella, 6.0. Sars 2. exilis, 6. O. Sars 3. pygmaea, 6. O. Sars Ectinosomidae Copepoda Suppl. Volume rd r.i- 1 F PI. XXV G. O. Sars, del. Pseudobradya ambigua, G. O. Sars Ectinosomidas Copepoda Suppl. Volume PI. XXVI - | 1 . w I - ' \ ; '^ . f< J i^\ ! G. O. Sars, del. Bradya Scotti, 6. O. Sars Copepoda Ectinosomidce Suppl. Volume PI. XXVII . . I G. O. Sars, del. _ 1. Bradya macrochaeta, G. 2. furcata, G. O. Sars Ectinosomidae Copepoda Suppl. Volume PI. XXVIII ^ 5^mrm / 1 I H I - . , . 1 G. O. Sars, del. 1. Bradya congenera, 6. 0. Sars 2. simulans, G. 0. Sars Ectinosomidae Copepoda Suppl. Volume PI. XXIX I - I ; / . G. O. Sars, del. Halophytophilus spinicornis, 6. O. Sars Harpacticidae Copepoda Suppl. Volume Pi. XXX I 1 G. O. Sars, del. Harpacticus tenellus, 6. 0. Sars Idyaeidae Copepoda Suppl. Volume pi. xxxi ^JSI '-'^\ S ' t G. O. Sars, del. Idyaea graciloides, G. O. Sars Idyaeidae Copepoda Suppl. Volume PI. XXXII G. O. Sars, del. Idyaea compacta, 6. O. Sars AN ACCOUNT OF THE CRUSTACEA OF NOR WAY WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES BY G. O. SARS VOL. VII COPEPODA SUPPLEMENT PARTS V & VI HARPACTICOIDA (continued) WITH 16 AUTOTYPIC PLATES BERGEN PUBLISHED BYTHE BERGEN MUSEUM SOLO BY ALB. CAMMERMEYERS'S FORL.AG. CHRISTIANIA 1920 -- Antennas and oral parts built on the very same type as in the 2 other known species. 1st pair of legs likewise of a very similar structure, the inner ram us being considerably longer than the outer, and only composed of 2 joints very sharply defined from each other, the distal one slightly shorter and much narrower than the proximal one, and armed at the tip with 2 exceedingly slender elaw-like spines accompanied inside by a small bristle; inner edge of this joint carrying 2 somewhat larger setae. The 3 succeeding pairs with the basal part rather broad and flattened, rami slender and of nearly equal length. Last pair of legs very narrow, with the proximal joint simple cylindric in shape, not expanded inside, distal joint a little longer than the proximal one, and conically tapered, with 3 small setae on the tip and another somewhat larger seta inside near the base. Colour of the living animal not yet ascertained. Length of adult female 0.58 mm. Remarks. The' above-described form is unquestionably referable to the genus Idyella, as defined by the present author, exhibiting, as it does, a struc- ture of the several appendages very similar to that found in the 2 other known species. It is however of considerably larger size than either of them and also of a comparatively more robust form of the body. Occurrence. A solitary female specimen only of this form has as yet come under my notice. It was found in a sample taken some years ago out- side Christiansand from a depth of about 30 fathoms. 42. Idyella exigua, G. O. Sars. See Vol. V, p. 101, Pi. LVIII, fig. 2. (PI. XXXIII, fig. 2). Remarks. The female of this species has been described and figured in Vol. V from some specimens taken at Bukken, south west coast of Norway. 1 have subsequently found this form not unfrequently in several places on the south coast, Korshavn, Lillesand, Riser, in depths ranging from 20 to 60 fathoms. Male specimens are very rarely met with, and may also easily escape attention on account of their small size. On the accompanying plate I have given some detail-figures of such a specimen, elucidating the rather well-marked sexual differences in the structure of the anterior antennas and the 2nd and last pairs of legs. 8 Crustacea. 54 Gen. Idyanthe, G. O. Sars. Remarks. This name was proposed by the present author in 1909, to replace Idyopsis, the latter name having been preoccupied. 43. Idyanthe dilatata, G. O. Sars. See Vol. V, p. 98, PI. LVII, fig. 1. (PI. XXXIII, fig. 3). Remarks. Of this form also only the female sex has been described. The male, of which a solitary specimen was obtained at Riser, differs from the female in a much similar manner to that found in Idyella. On the accom- panying plate the inner ramus of a leg of the 2nd pair from this male specimen is figured. Fam. Diosaccidae. Gen. Stenheliopsis, G. O. Sars. Remarks. Three well-defined species of this genus have been recorded in Vol. V, and a 4th species, nearly allied to the typical one, is now added, and will be described below. 44. Stenheliopsis affinis, G. O. Sars, n. sp. (PI. XXXIV). Specific Characters. Female. General form of body resembling that in 5. divaricata, being comparatively rather short and stout, with the anterior division considerably broader than the posterior. Cephalic segment large and evenly rounded in front; rostral plate prominent, linguiform, blunted at the tip. Urosome about the length of the anterior division and quite smooth. Caudal rami still more abruptly divergent than in the type species, but comparatively less slender, scarcely exceeding in length the last 2 caudal segments combined, each ramus armed at the somewhat thickened base with a transverse row of small denticles; innermost but one of the apical setae very strong and closely annulated in the middle, curving abruptly outwards and forwards in a sigmoid 55 manner and crossing the neighbouring seta at some distance from its base. Anterior antennas composed of 5 joints, the first 2 of which are much the largest, outer part of the antenna, as in the type species, abruptly recurved and densely clothed with strong curved seta. Posterior antennae and oral parts built on the same type as in 5". divaricata. Natatory legs likewise rather similar in structure, the inner ramus being in all of them only composed of 2 joints. Last pair of legs resembling in shape those in the type species, though having the inner expansion more distinctly defined and the marginal setae considerably longer. Ovisacs small, each containing only a single ovum. Colour whitish. Length of adult female 0.63 mm. Remarks. The present form is closely allied to the type species, 5. divaricata G. O. Sars, but of somewhat larger size, differing moreover in the comparatively less slender caudal rami, as also somewhat in the structure of the anterior antennae and the last pair of legs. Occurrence. Some specimens of this form, all of the female sex, were found at Riser in depths ranging from 30 to 50 fathoms, muddy bottom. Fam. Canthocamptidae. Gen. Attheyella, Brady. 45. Attheyella Schmeili, (Mrazek). (PI. XXXV). Canthocamplns Schmeilii, Mrazek, Beitrag zur Kenntniss der Harpacticidenfauna des Siisswassers. Zool. Jahrb. Vol. 7, p. 116, PI. 7, figs. 107117. Specific Characters. Female. Body comparatively slender and only slightly tapered behind, with all the segments distinctly denticulated along the hind edge dorsally. Cephalic segment about the length of the 3 succeeding segments combined, and broadly rounded in front, without any distinctly defined rostral projection. Urosome almost as long as the anterior division; genital segment somewhat shorter than the 2 succeeding segments combined; last segment well developed and of about same size as the preceding segment; anal opercle only slightly prominent, and obtusely truncated at the end, with the edge very finely denticulated. Caudal rami comparatively large, exceeding 56_ somewhat in length the anal segment, and obpyriform in outline, being rather broad at the base and gradually tapered distally, inner edge considerably bulged at the base and, like the outer, coarsely ciliated; seta of outer edge attached far in front; dorsal seta well developed and issuing a little farther behind; apex provided with only a single well-developed seta flanked by 2 small bristles. Anterior antennae a little shorter than the cephalic segment, with the joints rather sharply marked off from each other, terminal part a little shorter than the proximal one. Posterior antennae with the outer ramus comparatively small, though distinctly biarticulate, distal joint short, carrying on the tip a stout spine and a short seta. Mandibles with the palp very small, uniarticulate, with 2 apical setae. Maxillae and maxillipeds of normal structure. 1st pair of legs with the inner ramus considerably longer than the outer, though only composed of 2 joints; middle joint of outer ramus wanting the usual seta inside. The 3 succeeding pairs of legs having the outer ramus rather strongly built, with the spines very coarse; inner ramus, as usual, poorly developed, biarticulate, with the distal joint very narrow and only carrying a single apical seta. Last pair of legs of moderate size, with the distal joint oval in form and edged with 5 setae, the middle one small and not ciliated; inner expansion of proximal joint narrow linguiform and not extending as far as the distal joint, marginal setae 5 in number. Male smaller than female and exhibiting the usual sexual differences, being moreover distinguished by the much smaller size of the caudal rami. Inner ramus of 2nd pair of legs comparatively larger than in female, extending about to the middle of the terminal joint of the outer; that of 3rd pair trans- formed in the usual manner, being distinctly 3-articulate, with the middle joint produced at the end outside to a strong mucroniform process. 4th pair of legs with the spine attached to the middle joint of the outer ramus very strong and somewhat twisted; inner ramus very small and tipped with a strong spiniform seta and a much smaller bristle. Last pair of legs, as usual, much reduced in size. Colour witish gray, with a faint yellow tinge. Length of adult female 0.63 mm. Remarks. This form, first described by Mrazek as a species of Can- thocaniptus, ought evidently to be referred to the present genus, as defined in Vol. V. It is easily recognised by the comparatively large size of the caudal rami, which however, unlike what is generally the case, exhibit a somewhat different appearance in the two sexes. '57 Occurrence. Like the other known species of the present genus, 'this form is exclusively an inhabitant of fresh water. The only locality where -I as yet have met with it, is the lake Vansjo near Moss. It occurred here occasion- ally, together with Moraria brevipes G. O. Sars, in a depth of 36 fathoms, muddy bottom. Distribution. Bohemia (Mrazek), British Isles (Scott), Sweden (Lilljeborg). Gen. Ameira, Boeck. 46. Ameira dubia, G. O. Sars, n. sp. (PI. XXXVI). Specific Characters. Female. Body comparatively slender, with the anterior division conspicuously dilated in its anterior part. Cephalic segment large, equalling tri length the 3 succeeding segments combined, frontal edge slightly angular, but without any distinctly defined rostrum. Urosome rather narrow, equalling in length about Vj of the anterior division; genital segment longer than the 2 succeeding segments combined; last segment fully as large as the preceding one. Caudal rami short, being only slightly longer than they are broad, and somewhat divergent; apical setae well developed. Anterior antennae fully as long as the cephalic segment and distinctly 8-artieulate, ter- minal part exceeding half the length of the proximale one. Posterior antennae and oral parts of normal structure. 1st pair of legs imperfectly prehensile, the inner ramus being only slightly longer than the outer, with the 1st joint scarcely longer than the other 2 combined. The 3 succeeding pairs of legs of normal appearance, except that the terminal joint of the outer ramus in the 3rd and 4th pairs has inside 3, instead of 2 setae. Last pair of legs with the distal joint rather narrow, oblong in form, and somewhat constricted at the base, marginal setae 6 in number; inner expansion of proximal joint comparatively large, broadly linguiform, and extending beyond the middle of the distal joint; marginal setae rather strong and 5 in number. Colour not yet ascertained. Length of adult female 0.90 mm. Remarks. This is a somewhat anomalous form, differing from the more typical species of the present genus by the imperfectly prehensile cha- racter of the 1st pair of legs and the greater number of setae on some of the succeeding pairs. In these respects it agrees with the aberrant species, A. simplex Scott, and should perhaps, together with this species, be included in a 58 particular genus intermediate between Ameira and Parameira. It is of rather large size, as compared with the other known species. Occurrence. Two female specimens of the present form were found in a sample taken at Riser from a depth of about 30 fathoms. 47. Ameira exilis, Scott. (PI. XXXVII). Ameira exilis, Scott, Twelfth Ann. Report of the Fishery Board for Scotland, Part 111, p. 2-12, PI. X, figs. 1-12. Specific Characters. Male. Body exceedingly slender and narrow, linear in form, with the anterior division scarcely broader than the posterior. Cephalic segment about the length of the 2 succeeding segments combined and obtusely blunted in front, rostral projection inconspicuous. Urosome fully as long as the anterior division, with the segments subequal in size and almost perfectly smooth. Caudal rami comparatively short, being scarcely more than half as long as the anal segment; apical setae of moderate length. Anterior antennae about the length of the first 2 body-segments combined, and very conspicuously hinged, the middle portion being considerably dilated; terminal part composed of 3 elongated joints, the last clothed with long curved setae. Posterior antennae with the outer ramus biarticulate, distal joint however very small and less distinctly defined at the base. Mandibles with the palp of unusual size, its proximal joint forming inside a broad lamellar expansion armed with 3 strong, spiniform setae; distal joint narrow, sublinear in form. Maxillae and maxillipeds of normal structure. 1st pair of legs distinctly prehen- sile, the inner ramus being much longer than the outer, with the last 2 joints bent inwards, and combined about the length of the 1st joint; middle joint of outer ramus with a well-defined seta inside, wanting in the other known species; spine issuing from the inner corner of the 2nd basal joint very strong and sub-hamate at the tip. The 3 succeeding pairs of legs of normal structure and rather slender, especially the 4th pah, the outer ramus of which is fully twice as long as the inner. Last pair of legs more fully developed than is generally the case in male specimens; distal joint oval in form and provided with 6 marginal setae, 4 of which issue from the obtusely blunted end, one of the latter (the innermost but one) very much elongated; inner expansion of proximal joint well developed and rather prominent, extending about to the middle of the distal joint, marginal setae 5 in number, the outermost but one the longest. Colour whitish, pellucid. Length of the specimen examined 1.12 mm. Remarks. The above described form is evidently referable to the large species recorded by Scott as A. exilis and observed by that author in both sexes. Mr. Scott states the length of the adult female to be no less than 1.40 mm., and the present form accordingly grows to a size far exceeding that in any ot the other known species of Ameira. Occurrence. A solitary male specimen only of this form has as yet come under my notice. It was captured at Riser from a depth of about 20 fathoms. Distribution. Scottish coast (Scott). Gen. Parameira, G. O. Sars. Remarks. Of this genus 4 well-defined species have been recorded by the present author, 3 from the Norwegian coast and one from the Polar Islands North of Grinnels Land (2nd Fram Expedition). Two additional species, both of which have been previously observed by Scott, will be described below. 48. Parameira longiremis, (Scott). (PI. XXXVIII, fig. 1). Ameira longiremis, Scott, Twelfth Annual Report of the Fishery Bo;ird for Scotland, Part 111, p. 241, PI. V, figs. 29-32; PI. VI, figs. 1-5. Specific Characters. -Female. Body comparatively short and robust, with the 2 chief divisions rather sharply marked off from each other. Cephalic segment about the length of the 2 succeeding segments combined and evenly rounded in front, rostral projection inconspicuous. Urosome much shorter than the anterior division and almost of equal width throughout; genital segment large, exceeding somewhat in length the 2 succeeding segments com- bined; last segment scarcely shorter than the preceding one, with the anal opercle considerably prominent and narrowly rounded at the end. Caudal rarni very small and remote from each other; apical setae of moderate length. An- terior antennae comparatively short and stout, not attaining the length of the cephalic segment, 2nd joint only slightly longer than it is broad. Posterior antennae with the outer ramus very small, uniarticulate, carrying 2 short setae, the one apical, the other lateral. Oral parts normal. 1st pair of legs with the inner ramus considerably longer than the outer, its 1st joint rather dilated and about the length of the terminal joint, middle joint comparatively short. The 3 succeeding pairs of legs exhibiting the structure characteristic of the genus. Last pair of legs with, the distal joint exceedingly slender and narrow, sublinear in form, being fully 5 times as long as it is broad, and clothed on both edges with scattered hairs; marginal setae 5 in number, all issuing from the end of the joint; inner expansion of proximal joint triangular in form and carrying 5 strong setae. Colour not yet ascertained. Length of adult female 0.58 mm. Remarks. Though rather inferior in size, the above-described form agress pretty well with the description and figures given by Scott of his Ameira longiremis, and its identity with that species seems to me therefore to be beyond doubt. It is unquestionably referable to the genus Parameira, as defined by the present author, and may be recognised from the other species of that genus by the comparatively robust form of the body, and more par- ticularly by the very slender and narrow distal joint of the last pair of legs. Occurrence. Some few specimens of this form, all of the female sex, were picked up from samples taken at Korshavn in depths ranging from 30 to 50 fathoms, muddy sand. 49. Parameira intermedia, (Scott). (PI. XXXVIII, fig. 2). Ameira longiremis. var. intermedia, Scott, Twelfth Annual Report of the Fishery Board for Scotland, Part 111, p. 242, PI. VI, figs. (5-14. Specific Characters,- Female. Body considerably more slender than in the preceding species, with the anterior and posterior divisions of nearly equal length. Last caudal segment a little shorter than the preceding one, with the anal opercle less prominent and evenly rounded at the end. Caudal rami a little longer than they are broad; apical setae of moderate length. Anterior antennae comparatively shorter than in the preceding species, other- wise of a very similar structure. Posterior antennas with the outer ramus, as in that species, very small, uniarticulate, but rather narrower, with both setae issuing from the end. 1st pair of legs resembling in structure those in P. longiremis, inner ramus however comparatively shorter, with all 3 joints of about equal length. Last pair of legs with the distal joint not nearly so elongated as in the preceeing species and oblong oval in form; inner expansion 61 of proximal joint extending about to the middle of the distal joint, and having the marginal setae less unequal in length than in the preceding species. Colour not yet ascertained. Length of adult female 0.62 mm. Remarks. The present form is considered by Scott to be only a variety of the preceding species. I think however that the differences indicated in the above diagnosis may suffice for warranting its specific distinctness. Occurrence. Qi this species also only a small number of specimens have as yet come under my notice. They were obtained from the same samples as the preceding species. Distribution. Scottish coast (Scott). Gen. Pseudameira, G. O. Sars. Remarks. This genus was established by the present author in the year 1911, to comprise 2 well defined species, both obtained at Korshavn. I am now enabled to add 2 new species of this genus from another locality of the Norwegian coast. 50. Pseudameira gracilis, G. O. Sars, n. sp. (PI. XXXIX). Specific Characters. Female. Body much more slender and elongated than in either of the 2 previously described species, with the anterior division only slightly broader than the posterior. Cephalic segment equalling in length the 3 succeeding segments combined and rounded in front; rostral prominence small, but well defined, acuminate. Urosome about the length of the anterior division and nearly smooth; genital segment comparatively large, equalling in length the 3 succeeding segments combined, and distinctly subdivided in the middle; last segment much shorter than the preceding one. Caudal rami con- siderably produced, equalling in length the last 2 caudal segments combined, and narrow linear in form; apical setae not much elongated. Anterior antennae short and stout, not nearly attaining the length of the cephalic segment, but composed of 8 well defined joints, the 2nd of which is the largest and of rounded oval form, with the outer edge arcuate and clothed with stiff hairs; terminal part, comprising the 4 outer joints, short, scarcely exceeding the 2 preceding joints combined, and clothed with long curved setae. Posterior 9 Crustacea. 62 antennae with the outer ramus very narrow, bisetose. Oral parts normal. 1st pair of legs with the inner ramus scarcely longer than the outer, its terminal joint somewhat exceeding the middle one in length. The 3 succeeding pairs of legs comparatively strongly built, and resembling somewhat in structure those in P. furcata, the inner ramus being rather produced and extending beyond the outer, its 1st joint rather dilated and, as in P. furcata, armed inside near the base with a strong spine, replacing the usual seta, inner edge of the joint beyond the spine densely spinulose; middle joint produced at the end inside to a well developed spiniform process. 2nd basal joint of these legs armed inside with 4 5 coarse denticles. Last pair of legs of comparatively small size; distal joint oval quadrangular in form and remarkably constricted at the base, inner edge bulging and fringed with long cilia; marginal seta? 5 in number, the 2 innermost ones rather slender; inner expansion of proximal joint short and broad, with 5 marginal setae. Male, as usual, smaller than female and easily recognisable by the distinctly hinged anterior antennae; none of the legs transformed. Colour whitish. Length of adult female 0.75 mm. Remarks. The present form is nearly allied to P. furcata, but of considerably larger size, and moreover at once distinguished by the much more slender and elongated form of the body. It also exhibits some well-marked differences in the structural details, as indicated in the above diagnosis. Occurrence. I have found this form not unfrequently at Ris0r in depths ranging from 30 to 60 fathoms, muddy sand. 51. Pseudameira mixta, G. O. Sars, n. sp. (PI. XL). Specific Characters. Female. Body of a similar slender form to that of the preceding species, with the anterior division only slightly broader than the posterior. Rostral prominence well marked, but very small, acute. Urosome nearly as long as the anterior division, its last segment of about same size as the preceding one. Caudal rami less produced than in the preceding species, being scarcely longer than the anal segment; apical setae rather slender. Ante- rior antennae still shorter than in the said species and only composed of 6 joints, 2nd joint with the outer edge perfectly smooth. Posterior antennae with the outer ramus slightly widening distally and carrying 3 setae, 2 apical and one lateral. 1st pair of legs with the inner ramus distinctly longer than the 63 outer, its joints of about equal length. The 3 succeeding pairs of legs rather slender, with the inner ramus longer than the outer (at least in 2nd and 3rd pairs), its 1st joint moderately dilated, with the seta of the inner edge very small, not spiniform, and attached beyond the middle, being accompanied behind by a number of thin spinules; 2nd joint not produced at the end inside. Last pair of legs with the distal joint comparatively small, rounded oval in form, and only provided with 4 marginal setae; inner expansion of proximal joint more produced than in the preceding species, extending almost as far as the distal joint, and obtusely truncated at the end, marginal setae 4 in number. Colour whitish. Length of adult female 0.60 mm. Remarks. The present form looks rather like P. gracilis in its out- ward appearance, but is of much smaller size, and moreover at once distinguished by the comparatively less produced caudal rami. In the structure of the several appendages it exhibits a somewhat mixed character; hence the specific name here proposed. Occurrence. Only very few specimens of this form have as yet come under my notice. They were taken at Ris0r from a depth of about 50 fathoms, muddy bottom. Gen. Stenocopia, G. O. Sars. Remarks. The type of this genus is the form described by Scott as Ameira longicandata, which however, as pointed out by the present author, must be discarded from the genus Ameira, as defined by Boeck. Two other well- defined species of the present genus have been recorded in Vol. V, and I now am enabled to add another species, to be described below. 52. Stenocopia minor, G. O. Sars, n. sp. (PL XLI). Specific Characters. Female. Body comparatively less slender than in the type species, with the anterior division slightly broader than the posterior. Cephalic segment about the length of the 3 succeeding segments combined, and projecting in front to a triangular rostral plate. Trunkal segments per- fectly smooth. Urosome (including the caudal rami) fully as long as the anterior division and only slightly tapered behind, its segments minutely denti- culate at the hind edge; genital segment of moderate size and imperfectly 64 subdivided in the middle; last segment considerably larger than the preceding one, with the anal operele somewhat prominent and broadly rounded at the end. Caudal rami slender and narrow, though less elongated than in the other known species, scarcely exceeding in length the anal segment; apical setae moderately slender. Anterior antennae rather narrow, exceeding somewhat in length the cephalic segment, and composed of 9 well defined joints clothed with comparatively long curved setae; 2nd joint the largest and about equalling in length the 2 succeeding joints combined; penultimate and antepenultimate jonts very small, but distinctly defined. Posterior antennae with the outer ramus narrow, biarticulate, and only provided with 2 setae. Oral parts agreeing in structure with those in the other species. 1st pair of legs with the inner ramus very slender, being fully twice as long as the outer; terminal joint of the latter only armed with 4 spiniform setae. The 3 succeeding pairs of legs exhibiting the slender form characteristic of the genus; inner ramus however com- paratively shorter than in the other species, with the terminal joint less pro- duced and the number of setae somewhat reduced. Last pair of legs with the distal joint narrow oblong in form, and less exserted at the tip than in the other species; marginal setae rather unequal in length and 5 in number; inner expansjon of proximal joint comparatively broad, but only very slightly pro- duced, and edged with 4 setae, the outermost one very small. Colour whitish grey. Length of abult female 0.70 mm. Remarks. The present form is nearly allied to the type species, S. longicaudata (Scott), but is rather inferior in size, and moreover at once distinguished from that species by the comparatively less elongated caudal rami. In the structural details also some well-marked differences are found, as indi- cated in the above diagnosis. Occurrence. Some few female specimen of this form were taken at Riser from a depth of about 50 fathoms, muddy bottom. Gen. Cletomesochra, G. O. Sars, n. Generic Characters. Body as a rule short and stout, with the anterior division more or less dilated. Cephalic segment of moderate size, and provided in front with a prominent triangular rostral plate defined behind by a well- marked transverse suture. Caudal rami small and widely apart. Anterior antennae comparatively short and stout, being only composed of 5 joints partly 65 clothed with pectinate setae, last joint large, conically produced at the end. Posterior antennae with the outer ramus distinctly biarticulate. Mandibular palp likewise biartieulate, with the outer ramus small or wanting. Maxillae with the exopodal lobe well defined, bisetose. 1st pair of legs with both rami 3-articulate, the inner one imperfectly prehensile, being far less produced than in Mesochra, and scarcely bent at the end; middle joint of outer ramus without any seta inside. The succeeding pairs of legs comparatively slender, with the outer ramus much longer than the inner, which is only composed of 2 joints. Last pair of legs with the distal joint more or less produced; inner expansion well developed. Remarks. This new genus is established to include the form described in Vol. V, p. 395, as Mesochra exigua. The rather aberrant characters of this small species were noted in that plase, and it was therefore only with some doubt referred to the genus Mesochra of Boeck. Having now had an oppor- tunity of examining some other forms agreeing pretty well in the more general characters with the above-mentioned species, I think that the establishment of the present genus may be fully justified. The most conspicuous differences from Mesochra are found in the structure of the anterior antennae and in that of the 1st pair of legs. The generic name here proposed alludes to the agreement in structure of the anterior antennae to those in some of the Cleto- didce. 3 new species referable to the present genus will be described below. 53. Cletomesochra major, G. O. Sars, n. sp. (PI. XLII). Specific Characters. Female. Body comparatively more slender than in the type species, with the anterior division only slightly broader than the posterior. Cephalic segment about the length of the 3 succeeding segments combined; rostral plate rather prominent and narrowly truncated at the tip. Urosome shorter than the anterior division and only very slightly tapered behind, its segments minutely denticulate at the hind edge; genital segment not fully attaining the length of the 2 succeding segments combined; last segment nearly as large as the preceding one, with the anal opercle broadly rounded and perfectly smooth. Caudal rami very small, quadrangular in form, with the apical setae comparatively short. Anterior antennae scarcely exceeding half the length of the cephalic segment; the first 3 joints rather thick and gradually somewhat diminishing in size, the other 2, representing the terminal part of the antenna, very unequal in size, the proximal one being quite short, 66_ the distal one large and conically produced at the end. Posterior antennae with the basal part not subdivided, outer ramus provided with 4 setae, 2 apical and 2 lateral. Mandibular palp comparatively small, with the proximal joint not expanded and without any trace of an outer ramus. 1st pair of legs with the inner ramus only slightly longer than the outer, and having all 3 joints of about equal length; terminal joint of outer ramus with only 2 spines and 2 geniculated setae. The 3 succeeding pairs of legs agreeing in structure with those in the type species. Last pair of legs with the distal joint of com- paratively smaller size, oblong oval in form, and having the edges nearly smooth, marginal setae 5 in number; inner expansion of proximal joint rather broad and obtusely truncated at the end, extending beyond the middle of the distal joint; marginal setae rather strong and successively increasing in length outwards. Colour whitish grey. Length of adult female 0.57 mm. Remarks. The present species is unquestionably congeneric with C. exigua, but of considerably larger size and somewhat more slender form of the body, differing moreover somewhat in the structure of the 1st and last pairs of legs, as also in the less perfectly developed mandibular palp. Occurrence. A solitary female specimen of this form was obtained last summer (1918) at Hvaler, outside the Christiania Fjord, from a depth of about 6 fathoms. 54. Cletomesochra nana. G. O. Sars, n. sp. (PI. XLIII). Specific Characters. Female. Body short and stout, resembling in shape that in the type species. Rostral plate somewhat less prominent than in C. major, but of a very similar form. Urosome much shorter than the anterior division, and of about equal width throughout. Caudal rami small, quadrangular in form, with the inner corner somewhat prominent. Anterior antennae almost exactly of same appearance as in the preceding species. Posterior antennae with the outer ramus slightly widening distally and carrying 5 setae, 3 apical and 2 lateral. Mandibular palp with the basal part rather narrow, but having outside a well-marked small joint tipped with a ciliated seta and representing the rudimentary outer ramus. 1st pair of legs with the inner ramus distinctly longer than the outer, its middle joint shorter than either of the other 2, which are of about equal length. The 3 succeeding pairs of 67_ legs exceedingly slender, with the terminal joint of outer ramus narrower than in the preceding species and almost as long at the other 2 combined. Last pair of legs with the distal joint narrow oblong in form and slightly tapered towards the end, 2 of the outer-edge setae attached near the base of the joint at some distance from the 3 other setae; inner expansion of proximal joint short and broad, transversely truncated at the end, and scarcely extending beyond the middle of the distal joint; marginal setae rather slender, the outermost one the longest. Colour not yet ascertained. Length of adult female 0.41 mm. Remarks. This form is still more closely allied to the type species, and may on the first sight easily be confounded with it. It is however of smaller size and, on a closer examination, exhibits also some well-marked differences in the structural details, as indicated in the above diagnosis. Occurrence. Some few female specimens of this dwarfed species were picked up from samples taken at Riser in depths ranging from 30 to 50 fathoms. 55. Cletomesochra rostrata, G. O. Sars, n. sp. (PI. XLIV). Specific Characters. Female. Body moderately slender, with the an- terior division conspicuously broader than the posterior. Cephalic segment comparatively large, occupying more than half the length of the anterior division; rostral plate greatly prominent and acutely produced at the end. Urosome somewhat shorter than the anterior division, with the segments rather sharply marked off from each other and distinctly spinulose at the hind edge; last segment of about same size as the preceding one and somewhat widening distally; anal opercle finely denticulate at the edge. Caudal rami oblong quadrangular in form, being somewhat longer than they are broad; apical setae rather slender. Anterior antennae of somewhat larger size than in the other species, though not nearly as long as the cephalic segment, 3rd joint remarkably produced at the end anteriorly. Posterior antennae with the outer ramus of moderate size and carrying 4 setae, 2 apical and 2 lateral. Mandi- bular palp with the basal part somewhat dilated and carrying outside a distinctly developed outer ramus. 1st pair of legs with the inner ramus slightly longer than the outer; terminal joint of the latter with 3 outer-edge spines. The 3 succeeding pairs of legs exceedingly slender, with the terminal joint of both rami narrow linear in form. Last pair of legs rather unlike those in the other species, distal joint narrow linear in form, with the 2 outermost setae much 68 longer than the other 3; inner expansion of proximal joint narrowly produced at the end and extending about to the middle of the distal joint; marginal setae only 4 in number. Colour not yet ascertained. Length of adult female 0.67 mm. Remarks. This is a very distinct and easily recognisable form, differ- ing conspicuously from the other species both in the outward appearance and in the structure of some of the appendages, though, according to the structure of the antennae and of the 1st pair of legs, apparently referable to the present genus. Occurrence. A solitary female specimen of this form was found in a sample taken at Riser from a depth of about 50 fathoms. Gen. Hemimesochra, G. O. Sars, n. Generic Characters. Body sub-clavate in form, being conspicuously tumefied in its anterior part and attenuated behind. Rostral plate small and deflexed, not sharply defined behind. Segments of urosome coarsely spinulose at the hind edge. Caudal rami of moderate size. Anterior antennas short and stout, 5-articulate, with some of the setae on the proximal part coarsely pectinate, last joint comparatively large, but not conically produced at the end and with some of the setae ciliated. Posterior antennae with the outer ramus very small, uniarticulate. Mandibles very strong, with the cutting edge imperfectly dentate; palp well developed, but without any distinctly defined outer ramus. Maxillae with the exopodal lobe obsolete. 1st pair of legs not prehensile, the inner ramus being very short and only composed of 2 joints. The 3 succeeding pairs of legs of a structure similar to that in Mesochra. Last pair of legs likewise built on the same type as in that genus, the distal joint being very small, not produced at the end. Remarks. This new genus is only founded on a single species, which however exhibits certain peculiarities in the structural details forbiding its reception into any of the known genera of the present family, though in some respects it would seem to approch somewhat the genus Cletomesochra. 69 56. Hemimesochra clavularis, G. O. Sars, n. sp. (PI. XLV). Specific Characters. Female. Body moderately slender, with the anterior division conspicuously inflated in front, almost clavate in form. Cepha- lic segment large and tumid, evenly rounded in front, with the rostral plate abruptly deflexed, so as not being visible in the dorsal view of the animal. Urosome comparatively narrow and somewhat shorter than the anterior division, with the segments sharply marked off from each other and distinctly spinulose at the hind edge, the spinules being arranged in small groups; last segment nearly as large as the preceding one, and having the anal opercle small and perfectly smooth. Caudal rami about the length of the anal segment and somewhat divergent, edges partly spinulose; apical setae of moderate length. Anterior antennas scarcely half as long as the cephalic segment, with the first 2 joints comparatively short and combined scarcely longer than the 3rd; last joint rather large and clothed with long and slender setae. Posterior antennae with the basal part distinctly subdivided, outer ramus carrying 3 setae, 2 apical and one lateral. Mandibular palp with the basal joint rather large, though not much expanded, and provided in the middle of the outer edge with a strong ciliated seta replacing the outer ramus. 1st pair of legs much smaller than the succeeding pairs, with the inner ramus scarcely extending beyond the middle of the terminal joint of the outer, its proximal joint somewhat expanded and carrying inside the usual ciliated seta, distal joint of about same length, but much narrower, and armed at the tip with a strong spine accompanied inside by 2 unequal setae; outer ramus without any setae inside, terminal joint with only 2 outer-edge spines. The 3 succeeding pairs of legs well developed, with the inner ramus somewhat exceeding half the length of the outer and resembling in shape that in Mesochra. Last pair of legs with the distal joint very small, sub-quadrangular in form, and only provided vvith 4 setae, the innermost of which is much elongated, the other 3 com- paratively short; inner expansion of proximal joint extending far beyond the distal joint and obtusely truncated at the end; marginal setae 4 in number and of very unequal length, the outermost but one much the largest. Colour not yet ascertained. Length of adult female 0.53 mm. Remarks.- The present form may be easily recognised from any of the other known Canthocamptidce by the peculiar clavate shape of the body, a character which has given rise to the specific name here proposed. 10 Crustacea. Occurrence. Two female specimens only of this peculiar form have as yet come under my notice. They were taken at Riser from a depth of about 50 fathoms, muddy bottom. Fam. Laophontidae. Gen. Laophonte, Philippi. 57. Laophonte brevifurca, G. O. Sars, n. sp. (PI. XLVI). Specific Characters. Female. Body moderately slender and slightly attenuated behind, with all the segments well marked off from each other. Cephalic segment nearly half the length of the anterior division; rostral pro- minence comparatively short, triangular, and obtusely pointed at the end. Urosome shorter than the anterior division, and having the lateral expansions of the anterior segments well marked and densely spinulose at the edge; last segment about twice as broad as it is long, anal opercle rounded and distinctly denticulate at the edge. Caudal rami very short, being scarcely longer than they are broad at the base; apical setae of moderate length. Anterior antennae comparatively short and only composed of 6 joints, the last 2 being con- fluent; 2nd joint rather broad, of rounded form, and without any projection of the outer edge. Posterior antennae and oral parts of normal structure. 1st pair of legs less strongly developed than usual, with the outer ramus distinctly 3-articulate and extending beyond the middle of the proximal joint of the inner. The 3 succeeding pairs of legs with the inner ramus scarcely half as long as the outer, and only provided with 3 setae at the end. Last pair of legs with the distal joint comparatively small, narrow sub-quadrangular in form, and carrying 5 marginal setae, all issuing from the nearly transversely trun- cated end, one of the setae (the innermost but one) much longer than the others; inner expansion of proximal joint rather produced, extending almost as far as the distal joint; marginal setas 4 in number. Colour whitish grey, with a faint yellow tinge. Length of adult female 0.70 mm. Remarks. The above-described form, though not exhibiting any more prominent peculiarity in its structure, does not agree fully with any of the 71 numerous species of the present genus as yet known. It may be best recognised by the very small size of the caudal rarni, a character which indeed has given rise to the specific name here proposed. Occurrence. A solitary female specimen of this form was found last summer (1918) at Hval0r, outside the Christiania Fjord, in a depth of about 6 fathoms. 58. Laophonte tenera, G. O. Sars, n. sp. (PI. XLVII). Specific Characters. Female. Body rather slender and narrow, rapidly tapered behind, with the segments sharply marked off from each other. Cephalic segment large and tumid, occupying fully half the length of the anterior division; its postero-lateral corners produced in a peculiar manner and curved upwards; rostral projection rather prominent, triangular, and minu- tely bilobular at the tip. Urosome almost as long as the anterior division, and having the lateral expansions of the segments rather prominent and densely spinulose at the edges; last segment scarcely broader than it is long and slightly widening distally, anal opercle finely denticulate at the edge. Caudal rami about twice as long as they are broad and considerably divergent; apical setae of moderate length. Anterior antennae more slender than in the preceding species, though not nearly attaining the length of the cephalic segment, and composed of 7 well defined joints; 2nd joint the largest and oblong oval in form, with a very small prominence of the outer margin. Posterior maxillipeds comparatively larger than in the preceding species. 1st pair of legs likewise more powerfully developed; outer ramus however rather small, not extending to the middle of the proximal joint of the outer, and only composed of 2 joints. The 3 succeeding pairs of legs of normal structure. Last pair of legs with the distal joint well developed, broadly spatulate in form, and provided with 5 marginal setae, the innermost but one the longest and issuing from a digitiform process of the joint; inner expansion of proximal joint short and broad, obtusely rounded, and not extending to the middle of the distal joint; marginal setae 4 in number. Male of smaller size than female and having the anterior antennae very strongly hinged. 2nd pair of legs with one of the setae attached to the distal joint of the inner ramus transformed in a similar manner to that found in L. brevirostris and allied species. 3rd pair of legs, as usual, much more strongly built than in female, with the inner ramus distinctly 3-articulate and 72 having the middle joint acutely produced at the end outside. Last pair of legs much reduced in size, distal joint rather narrow and only provided with 4 seta; inner expansion of proximal joint obsolete. Colour not yet ascertained. Length of adult female 0.60 mm. Remarks. This form seems to be nearest allied to L. macera G. O. Sars, but is of somewhat larger size, and moreover at once distinguished by the less elongated caudal rami. The shape of the last pair of legs is also rather different. Occurrence. Several specimens of this form, both males and females, were picked up from samples taken at Korshavn at depths ranging from 30 to 50 fathoms. 59. Laophonte abbreviata, G. O. Sars, n. sp. (PI. XLVIII). Specific Characters, Female. Body quite unusualy short and stout, and pronouncedly depressed in its anterior part. Cephalic segment of very large size, far exceeding in length the remaining part of the trunk, being broadest behind and gradually somewhat contracted in front; rostral projection rather prominent and somewhat blunted at the end, which appears slightly bilobular. Urosome somewhat tapered behind, and about the length of the cephalic segment; lateral expansions of the segments comparatively small, but well difined and densely spinulose at the edges; last segment, as usual, not expanded and about twice as broad at it is long; anal opercle distinctly denticulate at the edge. Caudal rami of moderate size, about the length of the anal segment, and somewhat divergent; apical setae rather slender. Anterior antennae moderately long and composed of 7 well defined joints, the 2nd of which is the largest and oval in form, without any distinct projection of the outer edge. Posterior antennas with the outer ramus normally developed, somewhat widening distally and provided with 4 subequal ciliated setae. Posterior maxillipeds rather powerful. 1st pair of legs likewise comparatively strongly built, with the outer ramus distinctly 3-articulate, and extending consideratly beyond the middle of the proximal joint of the inner. The 3 succeeding pairs of legs of normal structure. Last pair of legs, however, rather peculiar; distal joint com- paratively large and almost perfectly orbicular in outline, carrying 6 rather short setae, 2 of which are attached somewhat inside the edge; inner expansion of proximal joint quite short, with 5 marginal setae, the outermost one very small. Idyaeidas Copepoda Suppl. Volume PI. XXXIII , G. O. Sars, del. 1. Idyella major, 6. O. Sars 2. exigua, G. O. Sars 3. Idyanthe dilatata, G. O. Sars Diosaccidae Copepoda Suppl. Volume PI. XXXIV > ; v o t \ -rr G. O. Sars, del. Stenheliopsis affinis, 6- O. Sars Canthocamptidae Copepoda Suppl. Volume PI. xxxv sM - G. O. Sars, del. Attheyella Schmeili (Mrazek) Canthocamptidae Copepoda Suppl. Volume PI. XXXVI \f\ I y^ ft ' vyisD : ' r . \ v\\ : ' . // ' 1 f ' G. O. Sars, del. Ameira dubia, 6. 0. Sars Canthocamptidae Copepoda Suppl. Volume PI. XXXVII I . G. O. Sars, del. Ameira exilis, Scott Canthocamptidae Copepoda Suppl. Volume PI. XXXVIII o-fff- } ,1 <*. tS ' . a&L ' 7" i . j ; . * -tr ! j / ' \ V G. O. Sars, del. 1. Parameira longiremis (Scott) 2. intermedia (Scott) Canthocamptidae Copepoda Suppl. Volume PI. XXXIX G O Sars, del. Pseudameira gracilis, 6. O. Sars Canthocamptidae Copepoda Suppl. Volume PI. XL ! G. O. Sars, del. Pseudameira mixta, G. O. Sars Canthocamptidae Copepoda Suppl. Volume PI. XLI G. O. Sars, d = '. Sienocopia minor. 6 O, Sars Canthocamptidas Copepoda Suppl. Volume PI. XLII . G. O. Sars, del. Cletomesochra major, 6. O. Sars Canthocamptidae Copepoda Suppl. Volume PI. XLIII G. O. Sars, del. Cletomesochra nana, 6. O. Sars Canthocamptidae Copepoda Suppl. Volume PI. XLIV *+*< G. O. Sars, del. Cletomesochra rostrata, 6. O. Sars Canthocamptidae Copepoda Suppl. Volume PI. XLV i 6. O. Sars, del. Hemimesochra clavularis, 6. O. Sars Laophontidae Copepoda Suppl. Volume PI. XLVI 6. O. Sars, del. Laophonte brevifurca, G. O. Sars Laophontidas Copepoda Suppl. Volume PI. XLVII ; f y'l\ . / 6. O. Sars, del. Laophonte tenera, 6. 0. Sars Laophontidae Copepoda Suppl. Volume PI. XLVIII / o 'i j . / - _ .^ >-""" ^ : ' /r - - \ X , , j , ^' - ii h? / . ' , jS . \ \ 6. O. Sars, del. Laophonte abbreviate, G. O. Sars 73 Colour not yet ascertained. Length of the specimen examined 0.55 mm. Remarks. This form may at once be distinguished from any of the other known species by its quite unusually short and stout body. In the structural details it seems to come nearest to L. littoralis Scott, described in Vol. V, p. 255. On a closer comparison, however, some well marked diffe- rences are found to exist, especially as regards the outer ramus of the posterior antennae and the 1st and last pairs of legs. Occurrence. A solitary, apparently fully grown female specimen of this form was found in a sample taken al Korshavn from a depth of about 30 fathoms. Gen. Harrietella, Scott, 1906. Generic Characters. Body short and stout, with the anterior division pronouncedly depressed, the posterior much narrower. Rostral projection well defined and ciliated at the tip. Caudal rami comparatively short. Antennae and oral parts built on the same type as in Laophonte. The 3 anterior pairs of legs likewise of a very similar structure. 4th pair of legs, however, peculiarly developed, and much smaller than the 2 preceding pairs, with the number of joints in both rami reduced. Last pair of legs extended laterally; distal joint large, lamellar, proximal joint short and only very slightly expanded inside. 2 ovisacs present in female. Male unknown. Remarks. This genus was established in the year 1906 by Scott, to include a form previously described by him as a species of the genus Laophonte. Indeed, the affinity of this form to that genus is a very close one. Yet there are at least 2 characters which highly distinguish the present genus, and which alone seem to suffice for warranting its validity, viz., the peculiar structure of the 4th pair of legs and the presence in the female, as stated by Scott, of 2 ovisacs. Only a single species of this genus is as yet known. 60. Harrietella simulans, Scott. (PI. XL1X). Laophonte simulans, Scott, Twelfth Annual Report of the Fishery Board for Scotland, Part III, p. 248, PI. VII, figs. 24^32; PI. VIII, fig. 1. Specific Characters. Female. Body remarkably short and broad, with the anterior division flattened. Cephalic segment very large and expanded' 11 Crustacea. occupying more than half the length of the anterior division, lateral edges finely ciliated; rostral projection rather prominent, with the tip narrowly rounded off and fringed with delicate cilia between the 2 usual sensory hairs. The 2 succeeding segments with the lateral parts lamellarly expanded and finely ciliated at the edges; the 3rd trunkal segment somewhat less broad, with the epimeral plates less fully developed; last segment very short. Urosome scarcely more than half as long as the anterior division and much narrower, tapered behind; genital segment nearly twice as broad as it is long and distinctly subdivided in the middle; the succeeding segments without any distinctly defined lateral expansions, but, like the genital segment, ciliated at the edges; last segment scarcely smaller than the preceding one and having the anal opercle well developed and minutely denticulate at the edge. Caudal rami about the length of the anal segment and somewhat divergent; apical setae moderately elongate. Anterior antennae rather slender, though nM at- taining the length of the cephalic segment, and composed of 6 joints clothed with scattered rather long setae; 2nd joint somewhat dilated, but scarcely as long as the 3rd. Posterior antennae comparatively strongly built, with the spines attached to the terminal joint very coarse and somewhat curved at the tip; outer ramus small, uniarticulate, with 4 ciliated setae. Posterior maxillipeds very powerfully developed. 1st pair of legs also rather strongly built, with the inner ramus large and armed at the end with an unusually strong curved claw; outer ramus very narrow, 3-articulate, and extending a little beyond the middle of the proximal joint of the inner. The 2 succeeding pairs of legs of rather normale appearance. 4th pair of legs very unlike the preceding pairs and much smaller, 2nd basal joint produced outside to a long digitiform process ciliated on both edges and carrying on the tip the usual slender bristle; outer ramus only composed of 2 joints, the proximal of which is the shorter and provided outside with a thickish densely ciliated seta, distal joint of a somewhat irregular form and edged with 5 setae similar to that attached to the proximal joint, each seta springing off from a knob-like prominence of the edge; inner ramus composed of a single small joint carrying on the tip 2 setae. Last pair of legs with the proximal joint quite short and produced outside to a slender process tipped with a bristle, its inner part only very slightly expanded and provided with 3 marginal setae of about equal length; distal joint remarkably constricted at the base, but widening in its outer part to a broad hairy plate carrying 5 comparatively short marginal setae. Colour not yet ascertained. Length of adult female 0.51 mm. 75 Remarks. The outward appearance of the present form is so peculiar that it cannot be confounded with any other member of the family Laophontidce, though there are a few species which exhibit a somewhat similar short and flattened shape of the body, for instance the form described in Vol. V, p. 273 as Laophontodes expansus. This form is however otherwise very different. Occurence. A single female specimen only of this peculiar form has" hitherto come under my notice. It was found in the bottom residue of a large collecting bottle containing several marine animals taken by Mr. Kjaer in the neighbourhood of Drebak from a depth of about 50 fathoms. The specimen was fully grown, but wanted the ovisacs. Distribution. Scottish coast. Fam. Cletodidae. Gen. Cletodes, Brady. 61. Cletodes Sarsi, Scott. (PI. L). Cletodes Sarsii, Scott ; Twenty-third Annual Report of the Fishery Board for Scotland, Part III, p. 146, PI. XII, figs. 19. Specific Characters. Female. Body very slender and gradually tapered behind, with all the segments sharply marked off from each other. Cephalic segment comparatively large, equalling in length the 3 succeeding segments combined; rostral projection rather prominent and narrowly blunted at the tip. Urosome (including the caudal rami) nearly as long as the anterior division; genital segment not fully attaining the length of the 2 succeeding segments combined, and imperfectly subdivided in the middle; last segment comparatively small, with the anal opercle well marked and perfectly smooth. Caudal rami very slender and narrow, equalling about half the length of the remaining part of the tail, and slightly divergent; outer edge exhibiting at the end of the first Va of its length a well-marked notch, to which are attached 2 somewhat unequal bristles, another small bristle occurring near the end; dorsal seta issuing about in the middle; apical seta rather slender and flanked by 2 small bristles, the outer of which is partly connected with it at the base. Anterior antennae comparatively short and stout, scarcely exceeding half the length of 76 the cephalic segment, and composed of 5 joints, the 2nd of which is the largest and much longer than the 3rd; terminal joint oblong oval in form, with some of the setae distinctly ciliated. Posterior antennae and oral parts of the structure characteristic of the genus. Natatory legs rather poorly developed and not very dissimilar in structure; inner ramus in all of them considerably 'shorter than the outer and biarticulate; outer ramus without any setae inside. Last pair of legs with the distal joint long and narrow, sublinear in form, and provided with 4 marginal setae, 2 on the outer edge, one at the tip, and one on the inner edge, the latter very strong, spiniform; inner expansion of proximal joint forming a well defined narrow plate edged with 3 strong setae and extending about to the end of the first V;s of the distal joint. Male resembling the female in the general form of the body, but easely recognisable by the strongly hinged anterior antennae. Inner ramus of 3rd pair of legs conspicuously transformed, being distinctly 3-articulate with the middle joint armed at the end outside with a strong spine; terminal joint small, with 2 slender setae on the tip. Colour not yet ascertained. Length of adult female 0.62 mm. Remarks. The present species is easily recognised by the very slender and attenuated shape of the body, and more particularly by the structure of the last pair of legs and that of the caudal rami. Occurrence. Some few specimens of this form were picked up from samples taken at Riser and Korshavn in depths ranging from 30 to 60 fathoms Distribution. Scottish coast (Scott). 62. Cletodes pusillus, G. O. Sars, n. sp. (Pi. Li). Specific Characters. Female. Body of a similar slender and narrow shape to that in the preceding species, though somewhat less rapidly attenuated behind. Cephalic segment scarcely attaining the length of the 3 succeeding segments combined, and having the rostral projection less produced and blunted at the end. Urosome almost the length of the anterior division and nearly cylindrical in shape, with the last segment scarcely smaller than the preceding one. Caudal rami long and narrow, nearly attaining half the length of the remaining part of the tail; outer edg.e with a slight notch in front of the middle carrying a small bristle; dorsal seta issuing a little beyond this notch; apical seta about the length of the ramus. Anterior antennae comparatively 77 more slender than in the preceding species, though scarcely as long as the cephalic segment; 2nd joint of about same length as the 3rd, but somewhat broader. Posterior antennae with the outer ramus very narrow and only provided with a single seta issuing from the tip. Natatory legs comparatively more slender than in C. Sarsi, with the setae of the inner ramus reduced in number. Last pair of legs with the distal joint less slender, oblong fusiform in outline, and carrying 5 marginal setae, 2 on the outer edge, 2 on the tip, and one inside near the end, none of the setae spiniform ; inner expansion of proximal joint very small, nodiform, with only 2 unequal setae; digitiform process issuing from same joint outside exceedingly long and slender. Male exhibiting the usual sexual differences from the female, the anterior antennas being conspicuously hinged, and the inner ramus of 3rd pair of legs transformed in a similar manner to that in the preceding species. Colour not yet ascertained. Length of adult female 0.51 mm. Remarks. In the slender and narrow shape of the body this form resembles somewhat C. Sarsi. It is however rather inferior in size and, on a closer comparison, exhibits also several well-marked differences in the struc- tural details, as indicated in the above diagnosis. Occurrence. Of this form also only a small number of specimens have as yet come under my notice. They were found in samples taken at Riser from a depth of about 60 fathoms. 63. Cletodes leptostylis, G. O. Sars. (PI. LII). ? Syn: Cletodes longicaudata, Brady (not Boeck). Specific Characters. Female. Body slender and attenuated, with the segments sharply marked off from each other. Cephalic segment about the length of the 3 succeeding segments combined; rostral projection of. moderate size and terminating in 2 minute juxtaposed denticles. Urosome considerably exceeding in length the anterior division, and rapidly tapered behind; genital segment comparatively large and distinctly subdivided in the middle; last seg- ment much smaller than the preceding one. Caudal rami exceedingly narrow and elongated, occupying more than Vs of the entire length of the body; outer edge with a well-marked notch near te base carrying 2 well-developed bristles and with another smaller bristle close to the end; dorsal seta attached considerably in front of the middle; apical seta shorter than the ramus, and, 78_ as usual, flanked by 2 small bristles, the outer of which is connected with it at the base. Anterior antennae of moderate size, not fully attaining the length of the cephalic segment, with the first 2 joint comparatively short and combined scarcely longer than the 3rd. Posterior antennae with the outer ramus very small, bisetose. Natatory legs moderately slender, with the inner ramus in 1st pair nearly as long as the outer, in the succeeding pairs much shorter; outer ramus in the 2 anterior pairs without any setae inside, in the 2 posterior pairs with a well developed seta on the middle joint and 2 such setae inside the terminal joint, the latter joint unusually prolonged, exceeding in length the other 2 combined. Last pair of legs largely developed and highly chitinised; distal joint much elongated and provided with 5 exceedingly strong and densely plumose setae, 3 on the outer edge, one at the tip, and one on the inner edge near the end, each seta being "attached to a well defined knob-like prominence; proximal joint with the outer digitiform process long and narrow, inner expansion of the joint produced in the form of a narrow, somewhat curved ramus densely ciliated inside, and extending along the distal joint until its posterior Va part, outer part of the ramus armed with 4 slender spines. Colour not yet ascertained. Length of the specimen examined 0.55 mm. Remarks. The above described form agrees in almost all its details so closely with the species recorded by Brady under the name of Cletodes longicaudata, that I have been in much doubt, if it not more properly should be referred to that species, in spite of its much inferior size 1 ). In any case the specific name longicaudata cannot be retained for the present form, as this name had been previously assigned by Boeck to another species of the present genus (see Vol. V, p. 286). Occurrence. A solitary, apparently fully grown female specimen of this form was found in a sample taken at Riser from a depth of about 30 fathoms. Distribution. ?British Isles (Brady & Scott). 64. Cletodes perplexus, Scott. (PI. LIII). Cletodes perplexus, Scott, Seventeenth Annual Report of the Fishery Board for Scotland, Part III, p. 257, PI. XI, figs. 12-20; PI. XII, fig. 1. Specific Characters. Female. Body comparatively more robust than in any of the preceding species, and tapering somewhat behind. Cephalic *) Brady gives the length to 0.79 mm., and Scott to no less than 0.84 mm. 79 segment about the length of the 3 succeeding segments combined and broadly rounded in front; rostral projection rather prominent, and terminating in an acute somewhat recurved point. Last trunkal segment comparatively large and tumid. Urosome not fully attaining the length of the anterior division; genital segment fully as long as the 2 succeeding segments combined, and distinctly subdivided in the middle; last segment exceeding in length the preceding one and conspicuously contracted distally. Caudal rami rather slender and narrow, about half the length of the remaining part of the tail; outer edge with 2 successive small bristles in its anterior half; dorsal seta issuing at the end of the first Vs of the ramus; apical seta rather slender. Anterior antennae com- paratively short and stout, scarcely exceeding half the length of the cephalic segment; 2nd joint much the largest, being nearly twice as long as the 3rd. Posterior antennas rather strongly built, with the terminal joint considerably dilated at the end, innermost apical seta remarkably strong and cloted on the outer edge with long cilia; outer ramus more fully developed than in the other species and provided with 3 marginal setae. . Oral parts normal. Natatory legs likewise built in the usual manner, though comparatively rather small; outer ramus in all of them without any setae inside. Last pair of legs very peculiar and unlike those in any of the other known species; proximal joint without any bristle-bearing process outside, its inner part considerably expanded and highly chitinised carrying inside 2 successive spiniform setae and produced at the end to a long mucroniform process denticulated in its outer part and pointing obliquely backwards and outwards; distal joint very small and im- perfectly defined at the base, with 3 comparatively short setae. Male of about same size as female and very like it in its general appearance, though easily recognisable by the distinctly hinged anterior antennae. Last pair of legs scarcely different from those in female. Colour pale whitish grey. Length of adult female 0.55 mm. Remarks. The highly remarkable structure of the last pair of legs is sufficient for at once distinguishing the present form from any of the other known species. In the other structural details it shows itself however to be a true member of the present genus. Occurrence.- Two specimens only of this form, a female and a male, have as yet come under my notice. They were found last summer (1918) at Hvaler, outside the Christiania Fjord, in a depth of about 6 fathoms, muddy bottom. Distribuction. Scottish coast (Scott). so Gen. Mesocletodes, G. O. Sars. Remarks. This genus was established by the present author to include the form described by Scott as Cletodes irrasa, which I found differed in certain points so materially from the other members of the present family as more properly to be separated from them generically. The validity of this genus I am now -enabled to confirm by adding 3 other species which are evidently congeneric with the above-mentioned form. 65. Mesocletodes monensis, (Thompson). (PI. LIV). Cletodes monensis, I. C. Thompson, Proc. & Transact, of Liverpool Zool. Society, Vol. VII, p. 200, PL XXXIV. Specific Characters. Female. Body comparatively more slender than in the type species and about of equal width throughout; all the segments minutely denticulate at the hind edge. Cephalic segment about the length of the 3 succeeding segments combined and somewhat contracted in its anterior part; rostral projection well defined and slightly curved downwards, with the tip acutely pointed; dorsal face of the segment somewhat vaulted and ex- hibiting behind the middle a very conspicuous horn-like process curved back- wards. Urosome about the length of the anterior division; genital segment of moderate size and imperfectly subdivided in the middle; last segment nearly as large as the 2 preceding segments combined, and having the anal opercle some- what prominent and armed dorsally with 2 successive denticles, the posterior one rather coarse and pointing backwards. Caudal rami slender and narrow, though not nearly attaining half the length of the remaining part of the tail; outer edge with 2 small bristles, the one attached at a short distance from the base, the other close to the end; dorsal seta issuing somewhat in front of the middle; apical setae very unequal, the middle one much the largest and about as long as the ramus, the innermost extremely small. Anterior antennae rather slender, nearly attaining the length of the cephalic segment, and composed of 7 sharply defined joints clothed with comparatively short, partly spiniform setae; 2nd joint much the largest; antepenultimate joint about the length of the last 2 joints combined. Posterior antennae with the outer ramus very small, bisetose. Oral parts agreeing in structure with those in the type species. Natatory legs like- wise rather similar, though comparatively somewhat less slender; inner ramus very small, but, as in the type species, distinctly biarticulate. Last pair of legs confluent in the middle; distal joints narrow linear in form, not dilated 81 at the end, and provided with 6 marginal setae, 3 very small on the outer edge, and 3 on the tip; inner expansion of proximal joint more distinctly defined than in the type species, and carrying 3 well-developed marginal setae. Ovisac very small. Colour whitish grey. Length of adult female 0.87 mm. Remarks. The present form, first described by I. C. Thompson, may at once be distinguished from the type species, M. irrasus Scott, by the peculiar horn-like process springing off from the dorsal face of the cephalic segment. In the more general structural details it shows a near relationship to that species, though, on a closer comparison, some well-marked minor differences may be found to exist, especially as regards the mutual relations of the joints in the anterior antennae and the shape of the last pair of legs. Occurrence. I have only met with this form in a single locality on the Norwegian coast, viz., at Riser, where it occurred occasionally in a depth of about 50 fathoms, coarse muddy sand. All the specimens obtained were of the female sex. Distribution. Liverpool Bay (Thompson). 66. Mesocletodes abyssicola, (Scott). (PI. LV). Cletodes abyssicola, Scott, On some Entomostraca collected in the Arctic Seas by W. Bruce. Ann. Mag. Nat. Hist. ser. 7, Vol. VIII, p. 347, PI. V, figs. 18. Specific Characters. Female. Body comparatively a little less slender than in the preceding species, with the segments coarsely denticulate at the hind edge. Cephalic segment somewhat tumid, with the frontal part broadly rounded off; rostral projection very small, almost obsolete; dorsal face of the segment considerably vaulted and armed behind, as in the preceding species, with a strong spiniform process still more prominent and curved than in that species. Urosome, as in the other species of the present genus, nearly of uniform width throughout, with the last segment rather large; anal opercle tipped with a strong upturned tooth. Caudal rami very narrow and quite excessively produced, occupying more than Vs of the entire length of the body, each ramus provided in the middle with 2 small bristles, the one lateral, the other dorsal; apical setae very short. Anterior antennae comparatively slender, exceeding somewhat in length the cephalic segment, and, as in the preceding species, composed of 7 joints, the 2nd of which is rather broad, though 12 Crustacea. 82 scarcely as long as the 3rd; the 4 outer joints very narrow and subequal in size, constituting together the terminal part of the antenna, as shown by the position of the aesthectask which is attached to the 3rd instead, as usual, to the 4th joint. Posterior antennae with the outer ramus very minute and only tipped with a single seta. Oral parts scarcely different from those in the other species. Natatory legs with the inner ramus very small, uniarticulate; outer ramus in the 3 posterior pairs exceedingly slender and narrow. Last pair of legs with the proximal joint scarcely at all expanded inside, and only provided with a single small seta on the posterior edge; distal joint narrow linear in form, with a small bristle outside beyond the middle, and with 3 unequal apical setae. Colour pale whitish grey. Length of adult female 0.84 mm. Remarks. The near relationship of the present form to the preceding one is clearly sho^n by the presence of a quite similar spiniform process on the dorsal face of the cephalic segment. It is however at once distinguished from that species by the excessively prolonged and narrow caudal rami, as also by the very small rostral projection. Some aberrant characters, as to the struc- ture of the anterior antennae and legs, have moreover been indicated in the above diagnosis. Occurrence. 2 or 3 female specimens only of this form have as yet come under my notice. They were found at Ris0r at the considerable depth of about 100 fathoms, muddy bottom. Distribution. Arctic Sea (Scott). 67. Mesocletodes inermis, G. O. Sars, n. sp. (PI. LVI). Specific Characters. Female. Body resembling somewhat in shape that of M. monensis, though on the whole rather more robust. Cephalic seg- ment, as in that species, slightly contracted in front, with the rostral projection well defined and rather prominent, tridentate; dorsal face of the segment not much vaulted and without any trace of a spiniform process. Urosome about the length of the anterior division, with the last segment rather large; anal opercle not much prominent and edged with about 5 small denticles. Caudal rami only slightly longer than the anal segment, but of the usual narrow linear shape, with 2 small bristles, rather remote from each other, on the outer edge; dorsal seta issuing somewhat beyond the middle; apical setae comparatively 83 short. Anterior antennae rather slender, nearly attaining the length of the cephalic segment, and composed of 8 well defined joints, the 2nd of which is, as usual, the largest, though scarcely as long as the 2 succeeding joints combined, the 4 outer joints, composing the terminal part of the antenna, of about equal size. Posterior antennae comparatively small, with the outer ramus poorly developed, bisetose. Oral parts of the stucture characteristic of the genus. Natatory legs comparatively less slender than in the other species, and coarsely aculeate outside, inner ramus reduced to a minute nodiform prominence carrying in the 1st pair only one, in the other pairs 2 small bristles. Last pair of legs with the distal joint of the usual narrow linear form, and provided with 5 marginal setae, 3 apical and 2 lateral, the latter attached to the outer edge beyond the middle; inner expansion of proximal joint produced to a well defined narrow linguiform lamella carrying on the end 2 rather slender and distinctly ciliated setae accompanied outside by a very small spinule. Colour brownish grey. Length of adult female 0.86 mm. Remarks. This new species is nearly allied to M. monensis, the general form of the body being rather similar, though somewhat more robust. It is however at once distinguished from that species by the absolute absence of any dorsal process on the cephalic segment. The specific name here pro- posed alludes to this want. As to the structural details, it moreover differs in the distinctly 8-articulate anterior antennae and in the rudimentary condition of the inner ramus of the natatory legs. Occurrence. Several specimens of this form, all of the female sex, were found at Riser in depths ranging from 30 to 60 fathoms, coarse muddy sand. Gen. Eurycletodes, G. O. Sars. Remarks. Of this genus 4 species have been described in Vol. V of the present work. To these are now added 4 others, increasing the number of Norwegian species of this genus to 8 in all. 68. Eurycletodes serratus, G. O. Sars, n. sp. (PL LVII). Specific Characters. Female. Body comparatively short and stout, of nearly equal width throughout, with all the segments coarsely denticulate at the hind edge. Cephalic segment scarcely as long as the 2 succeeding seg- 84 ments combined, and produced in front to a rather prominent acutely pointed rostral projection. Urosome about the length of the anterior division, with the 3 anterior segments produced on each side to well-marked spiniform pro- minences, giving that part a pronouncedly serrate appearance; last segment very large and, viewed from above, regularly quadrangular in outline; anal opercle edged with scattered strong denticles (about 5 in number). Caudal rami resembling in shape those in E. laticaiidatus, being rather narrow and somewhat tapered distally; dorsal seta issuing from a knoblike prominence at a short distance from the end of the ramus. Anterior antennae not fully attaining the length of the cephalic segment and, as in the other known species, composed of 6 joints, 3 of which belong to the terminal part, 1st joint the largest, 2nd joint a little shorter than the 3rd; terminal part about the length of the 2 preceding joints combined, with the last joint rather produced. Posterior antennae without any trace of an outer ramus. Mandi- bular palp distinctly biarticulate. Posterior maxillipeds moderately strong. Natatory legs with both rami well developed; the inner one biarticulate and in 1st pair nearly as long as the outer, in the succeeding pairs rather shorter. Last pair of legs with the distal joint oblong oval in form and only slightly tapered distally, marginal setae 5 in number; inner expansion of prox- imal joint not much produced and carrying 3 subequal setae. Colour dark grey. Length of adult female 0.87 mm. Remarks. The present form is nearly allied to the type species, E. laticaiidatus (Boeck), agreeing with it rather closely in most of the structural details. It is however of considerably larger size, and moreover at once distinguished by the conspicuously serrated edges of the urosome, in which latter respect it more resembles E. latus (Scott). Occurrence. Some few female specimens of this fine species were taken at Ris0r from a depth of 60 80 fathoms, muddy bottom. 69. Eurycletodes oblongus, G. O. Sars, n. sp. (PI. LVIII). Specific Characters. Female. Body comparatively more slender than in the preceding species, oblong in form, with the segments less coarsely denticulated at the hind edges. Cephalic segment fully as long as the 3 suc- ceeding segments combined, and produced in front to a broadly triangular rostral projection. Urosome scarcely attaining the length of the anterior 85 division and somewhat less broad, with the anterior segments produced laterally to well defined, posteriorly-pointing acute projections; last segment very large, with the lateral edges somewhat arched and minutely denticulate; anal opercle edged with about 10 strong denticles. Caudal rami comparatively small, being only slightly longer than they are broad; dorsal seta issuing from a rather prominent tubercle somewhat in front of the middle; apical setae unusually short. Anterior antennae not nearly attaining the length of the cephalic seg- ment; 2nd joint shorter, but much broader than the 3rd; terminal part about the length of those joints combined. Posterior antennae rather small, with the outer ramus replaced by a simple seta. Posterior maxillipeds comparatively strong. Natatory legs with the inner ramus poorly developed, only consisting of a single joint, carrying in the 2 anterior pairs 4, in the 2 posterior pairs only 2 setae. Last pair of legs with the distal joint narrow oblong in form and only provided with 4 setae, 2 apical and 2 lateral; inner expansion of proximal joint conically produced, and extending about to the middle of the distal joint, tip provided with 2 subequal setae. Colour whitish grey. Length of adult female 0.78 mm. Remarks. In the structural details this form seems to approeh nearest to E. major G. O. Sars. It is however rather inferior in size and moreover at once distinguished by the well-marked lateral armature of the anterior seg- ments of the urosome, as also by the less produced caudal rami. Occurrence. Two female specimens only of this form have as yet come under my notice. They were taken at Ris0r from a depth of about 30 fathoms. 70. Eurycletodes aculeatus, G. O. Sars, n. sp. (PI. LIX). Specific Characters. Female. General form of the body somewhat resembling that in E. oblongus, though perhaps a little shorter and stouter. Cephalic segment scarcely longer than the 2 succeeding segments combined; rostral projection only slightly prominent and obtusely pointed at the end. Urosome about the length of the anterior division, and having the hind edges of the segments very coarsely dentate, the outermost tooth on the 2 anterior segments being much stronger than the others and projecting on each side. Last caudal segment large, with the lateral edges slightly convex and finely hairy; anal opercle broadly rounded off and edged with about 12 denticles of 86 moderate size. Caudal rami comparatively small, though somewhat longer than they are broad; dorsal seta issuing about in the middle from a well- marked knob-like prominence; apical setae of moderate length. Anterior antennae nearly attaining the length of the cephalic segment; 2nd joint rather short, scarcely more than half as long as the 3rd; 4th joint unusually pro- duced anteriorly. Posterior antennae, as in the preceding species, with the outer ramus replaced by a simple seta. Posterior maxillipeds moderately strong. Natatory legs with the inner ramus uniarticulate, largest on the 1st pair and successively diminishing in size on the succeeding pairs. Last pair of legs with the distal joint very narrow and somewhat tapered towards the end, car- rying 4 setae, the proximal one rather remote from the other 3, which issue from the outermost part of the joint; inner expansion of proximal joint only slightly produced and provided with 2 subequal setae. Colour whitish grey. Length of adult female 0.73 mm. Remarks. The present form may be easily recognised by the unusu- ally coarse dentation of the caudal segments, a character which has given rise to the specific name here proposed. In the structure of the several appendages it seems to come nearest to E. oblongus. Occurrence. Some female specimens of this form were obtained at Riser in a depth of about 50 fathoms, muddy bottom. It also occurs occasio- nally at Korshavn in about the same depth. 71. Eurycletodes minutus, G. O. Sars, n. sp. (PL LX). Specific Characters. Female. Body short and stout, with the anterior division conspicuously broader than the posterior and somewhat depressed. Cephalic segment comparatively large, considerably exceeding in length the 2 succeeding segments combined, and gradually somewhat contracted in front; rostral projection only slightly prominent and obtusely pointed at the end. Urosome much shorter than the anterior division and narrower than usual, with the segments uniformly denticulated at the hind edges and the lateral corners not produced; last segment, as usual, of rather large size, with the lateral edges slightly convex and finely hairy; anal opercle quite smooth at the edge. Caudal rami about twice as long as they are broad and only slightly tapered distally; dorsal seta issuing about in the middle; apical setae of moderate length. Antennae and oral parts resembling in structure those in 87 the 2 preceding species. Natatory legs with the inner ramus still more reduced in size and apparently quite wanting on the 4th pair; outer ramus in this and the 2 preceding pairs very slender and narrow. Last pair of legs with the distal joint narrow linear in form and imperfectly defined at the base, marginal setae rather small and 4 in number; inner expansion of proximal joint very slightly produced and carrying 2 unequal setae. Colour whitish grey. Length of adult female 0.53 mm. Remarks. This small species may be easily recognised by the some- what unusual shape of the body, the anterior division being, unlike what is generally the case, conspicuously broader than the posterior. In the structural details it shows itself however to be a true member of the present genus. Occurrence. Some few specimens of this form, all of the female sex, were found at Riser in depths ranging from 30 to 50 fathoms, muddy bottom. Gen. Leptocletodes, G. O. Sars, n. Generic Characters. Body of slender form, with very thin and fragile integuments. Rostral projection inconspicuous. Urosome narrower than the anterior division, with the segments scarcely denticulate behind; last segment comparatively large. Caudal rami narrow and rather far apart. Anterior antennae 7-articulate, with the terminal joint elongate. Posterior antennae small with the outer ramus imperfectly developed. Mandibular palp distinctly biarticu- late. Maxillae with a small exopodal lobe tipped with a single bristle. Max- illipeds normal. Natatory legs slender, with both rami well developed, the inner one shorter than the outer and 'biarticulate. Last pair of legs with the proximal joint scarcely expanded inside; distal joint long and slender. Male unknown. Remarks. This new genus is only founded on a single species, which however cannot properly be referred to any of the hitherto known genera of the present family, though in some respects apparently approaching somewhat the genus Eurycletodes. The generic name here proposed alludes both to the comparatively slender form of the body and to the very thin and fragile integuments. 72. Leptocletodes debilis, G. O. Sars, n. sp. (PI. LXI). Specific Characters. Female. Body rather slender and narrow, with the anterior division only slightly dilated, though somewhat broader than the posterior. Cephalic segment exceeding in length the 2 succeeding segments combined, and somewhat vaulted dorsally; frontal margin slightly produced in the middle, though not forming any true rostrum. Last trunkal segment com- paratively small. Urosome not attaining the length of the anterior division, and rather narrow, cylindrical in form; genital segment fully as long as the 2 succeeding segments combined and imperfectly subdivided in the middle; last segment oblong quadrangular in outline, with the anal opercle broadly truncated at the end and perfectly smooth. Caudal rami widely apart, and narrow linear in form, not however attaining the length of the anal segment, both the outer and inner edge carrying beyond the middle a small seta; dorsal seta issuing near the end of the ramus; apical setse rather slender. Anterior antennae fully as long as the cephalic segment and composed of 7 well defined joints clothed with scattered comparatively short setae; the first 2 joints about equal in size, each of them equalling in length the 2 succeeding joints combined; terminal part of the antenna, composed of the 3 outer joints, almost as long as the proximal one, with the last joint rather large, fully as long as the other 2 combined. Posterior antennae rather feeble, with the outer ramus very small, uniarticulate, and tipped by a single seta. 1st pair of natatory legs, as usual smaller than the others, with the rami less unequal in length, the outer one being only slightly longer than' the inner and without any setae inside. The 3 succeeding pairs of legs with the outer ramus very slender and narrow, inner one successively somewhat diminishing in length, extending in 2nd pair beyond the middle joint of the outer, in 4th pair only as far as the 1st joint of that ramus. Last pair of legs with the proximal joint produced outside to a long digitiform process tipped with a slender bristle, inner part of the joint not at all expanded, and only provided behind with a single seta arising from a knoblike prominence of the margin; distal joint greatly produced and narrow linear in form, though a little dilated in its outer part, and carrying 4 com- paratively small marginal setae, 2 lateral and 2 apical. Colour whitish pellucid. Length of adult female 0.63 mm. Remarks.- In its outward appearance this form somewhat reminds on Fultonia hirsuta Scott (see Vol. V, p. 341), which however otherwise is rather 89 different, and has been referred provisionally by the present author to another family, viz., the Tachidiidce. The great fragility of the animal renders its exact examination rather difficult, and has indeed given rise to the specific name here proposed. Occurrence. Some specimens of this form, all of the female sex, were found at Riser in depths ranging from 50 to 100 fathoms, muddy bottom. Gen. Pseudodetodes, G. O. Sars, n. Generic Characters. - - Body slender and attenuated, with strongly chitinised integuments, and all the segments distinctly denticulate at the hind edge. Cephalic segment peculiarly expanded below, and produced in front to a well defined rostral projection. Urosome with the segments somewhat expanded laterally; last segment .smaller than the preceding ones. Caudal rami somewhat produced and rather narrow. Anterior antennae of moderate size, but with the number of joints much reduced. Posterior antennas with the outer ramus well defined, uniarticulate. Mandibular palp likewise uniarticulate. Maxillae without any distinctly defined exopodal lobe. Anterior maxillipeds with 3 setiferous lobes inside the basal part. Posterior maxillipeds moderately strong. 1st pair of legs small, with both rami biarticulate; the 3 succeeding pairs with the outer ramus distinctly triarticulate and very slender, inner ramus biarticulate and shorter than the outer. Last pair of legs of rather a peculiar shape, the proximal joint being remarkably produced both outside and inside, distal joint comparatively small. Male unknown. Remarks. This genus also is only founded on a single species, which however exhibits several very conspicuous peculiarities both as to the outward appearance and the structural details, preventing its reference to any of the hitherto known genera of the present family. 73. Pseudodetodes typicus, G. O. Sars, n. sp. (PI. LXII). Specific Characters. Female. Body of rather slender form and gradu- ally attenuated behind, with the segments rather sharply marked off from each other. Cephalic segment of very large size, occupying rather more than half the length of the anterior division, and forming below on each side a broad 13 Crustacea. 90 lamellar expansion covering at the sides the oral area; rostral projection con- siderably prominent, with the end narrowly produced and terminating in 2 small juxtaposed points. Urosome somewhat shorter than the anterior division, with the lateral parts of the segments slightly prominent and rounded off; genital segment comparatively large and distinctly subdivided in the middle; last segment shorter than the preceding one, with the anal opercle coarsely denticulate at the edge; all the caudal segments containing within their lateral parts a very conspicuous rounded opaque body of apparently glandular nature. Caudal rami slightly exceeding in length the anal segment and rather narrow, with 2 juxtaposed bristles on the outer edge at a short distance from the end; dorsal seta issuing a little farther behind; apical setae very slender. Anterior antennae nearly as long as the cephalic segment, and only composed of 4 distinctly defined joints clothed with scattered comparatively short and stout setae; 2nd joint produced behind in the middle to a strong claw-like projection; 3rd joint about the length of the first 2 joints combined, and exhibiting at the end, in addition to the projection carrying the usual aesthetask, a small conical process tipped with a seta, and apparently representing the remnant of a small joint originally intercalated between it and the succeeding (last) joint, but otherwise wholly coalesced with the former; terminal joint about as long as the 3rd, but much narrower. Posterior antennae of moderate size; outer ramus formed by a small, but well defined joint carrying on the tip 2 somewhat unequal setae. 1st pair of legs much smaller than the succeeding ones and, as usual, armed at the inner corner of the 2nd basal joint with a deflexed spine; inner ramus somewhat shorter and much narrower than the outer, with the distal joint comparatively small, and carrying on the tip a slender seta accompanied by a short bristle; outer ramus without any setae inside, its distal joint of about same size as the proximal one, and armed at the end with 3 slender spines followed by a somewhat longer ciliated seta. The 3 succeeding pairs of legs with the outer ramus very slender and narrow and without any seta inside the 1st joint; inner ramus in 2nd pair extending about to the end of the middle joint of the outer, in the 3rd and 4th pairs successively shorter. Last pair of legs with the distal joint very small, oval in form, and edged with 4 setae; proximal joint produced outside to a long digitiform process tipped with a slender bristle; inner expansion exserted to a long conical lappet extending far beyond the distal joint, and tipped with a slender seta accompanied outside by a very minute bristle. Colour pale yellowish grey. Length of adult female 0.62 mm. 91 Remarks. In the slender and attenuated shape of the body this form bears a general resemblance to some species of the genus Cletodes. It is however at once recognised from them by the peculiar shape of the cephalic segment, as also by the rather different structure of the anterior antennae and of the 1st and last pairs of legs. Occurrence. Some few female specimens of this peculiar form were found at Riser in depths ranging from 30 to 60 fathoms, coarse muddy sand. Gen. Nannopus, Brady. Remarks. Two species only of this genus are as yet known, the one (the type), N. palustris Brady, occurring in brackisk water on the coasts of northern Europe and described in Vol. V, p. 307, the other having been recorded by the present author form the great fresh-water lake Tanganyika in Central Africa, under the name of Ilyophilus perplexus. I am now enabled to add a 3rd very distinct species, which, unlike the other two, is a true marine and deep-water form. 74. Nannopus abyssi, G. O. Sars, n. sp. (PI. XLIII). Specific Characters. Female. Body short and stout, gradually tapered behind, with the segments not very sharply marked off from each other and perfectly smooth. Eye absent. Cephalic segment about equalling in length the 3 succeeding segments combined, and evenly vaulted above; rostral pro- jection abruptly deflexed, with the tip obtusely pointed and only provided on each side with a single sensory hair. Urosome scarcely longer than the exposed part of the trunk; genital segment comparatively large and imper- fectly subdivided in the middle; last segment much shorter than the preceding one, with the anal opercle very small. Caudal rami about twice as long as they are broad at the base, and somewhat tapering distally, each ramus armed, inside the 2 juxtaposed bristles of the outer edge, with a short transverse row of small spinules; dorsal seta issuing near the base of the ramus; apical setae comparatively short, the middle one of quite normal appearance. Anterior antennae short and stout, scarcely exceeding half the length of the cephalic segment and, as in the other 2 species, composed of 5 joints clothed with rather strong, for the most part ciliated setae; the first 3 joints successively diminishing in size, the 3rd being rather produced at the end anteriorly, the 92 outer 2 joints, composing the terminal part of the antenna, abruptly much smaller and subequal in size, the last one carrying behind an unusually thick and coarsely ciliated seta. Posterior antennae very strongly built, with the terminal joint coarsely aculeate outside; outer ramus comparatively large, lamellar, with 6 strong marginal setae. Mandibular palp likewise very fully developed and distinctly biramous, with the basal part considerably expanded and provided at the prominent inner corner with 4 strong curved setae; both rami uniarticulate and of unequal size, the inner one being much the larger. Maxillae with both the exopodal and epipodal lobes well defined. Maxillipeds resembling in structure those in the other 2 species. 1st pair of legs well developed and coarsely aculeate outside; inner ramus biarticulate and a little shorter than the outer. The 3 succeeding pairs of legs without the slightest trace of an inner ramus; outer ramus normally developed and only sligtly longer than that of the 1st pair. Last pair of legs extremely small, though distinctly biarticulate, both joints simple, not expanded. Ovisac globular, with only a small number of comparatively large ova. Colour whitish grey. Length of adult female 0.68 mm. Remarks. This is a very distinct form, differing in some points rather markedly from the 2 previously known species, though evidently referable to the same genus. The most prominent differences relate to the great reduction of the last pair of legs and the absolute absence of an inner ramus on the 3 posterior pairs of natatory legs. On the other hand are the antennae and the oral parts rather more fully developed than in those species, though built on the very same type Occurrence. A solitary specimen only of this interesting form, an ovigerous female, has as yet come under my notice. It was found at Riser in the considerable depth of nearabout 100 fathoms, muddy bottom. Fam. Tachidiidae. Gen. Danielssenia, Boeck. Remarks. This genus, which is identical with Jonesiella of Brady, comprises as yet 4 species, 2 of which are described in Vol. V of the present work, the other 2 being recorded from the Arctic Seas. I am now enabled to add a 5th well defined and rather large species, to be described below. Laophontidae Copepoda Supp!. Volume PI. XLIX G. O. Sars, del. Harietella simulans. Scott Cletodida3 Copepoda Suppl. Volume PI. L G. O. Sars, del. Cletodes Sarsi, Scott Cletodidae Copepoda Suppl. Volume PI. LI T 6. O. Sars, del. Cletodes pusillus, 6. 0. Sars Cletodidae Copepoda Suppl. Volume f "* o t PI. Lll 6. O. Sars, del. Cletodes leptostylis, 6. 0. Sars Cletodidae Copepoda Suppl. Volume PL Llll 6. O. Sars, del. Cletodes perplexus, Scott Copepoda Cletodidae Suppl. Volume PI. |_IV G. O. Sars, del. Mesocletodes monensis, (Thomps.) Cletodidae Copepoda Suppl. Volume PI. LV G. O. Sars, del. Mesocletodes abyssicola. (Scott) Cletodidae Copepoda Suppl. Volume PI. LVI r= G. O. Sars. del. Mesocletodes inermis, G. O. Sars Cletodidae Copepoda Suppl. Volume PI. LVII ct- G. O. Sars, del. Eurycletodes serratus, 6. O. Sars Cletodidae Copepoda Suppl. Volume ff I -^ r \ '" ' '-'-.'- ' PI. LVIII G. O. Sars, del. Eurycletodes oblongus, 6. 0. Sars Cletodidae Copepoda Suppl. Volume PI. LIX - ""^v j\L. G. O. Sars, del. Eurycletodes aculeatus, G. O. Sars Cletodidae Copepoda Suppl. Volume PI. LX - 6. O. Sars, del. Eurycletodes minutus, G. 0. Sars Cletodidae Copepoda Suppl. Volume PI. LXI / 4-A. ./? ; 6. O. Sars, del. Leptocletodes debilis, 6. O. Sars Cletodidae Copepoda Suppl. Volume PI. LXII . ,- G. O. Sars, del. Pseudocletodes iypicus, G. O. Sars Cletodidae Copepoda Suppl. Volume PI. LXIII ^ , . G. O. Sars, del. Nannopus abyssi, G. 0. Sars Tachidiidae Copepoda Suppl. Volume PI. LXIV F !>* f \ G. O. Sars, del. Danielssenia robusta, 6. O. Sars AN ACCOUNT OF THE CRUSTACEA OF NOR WAY WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES BY G. O. SARS VOL. VII COPEPODA SUPPLEMENT PARTS IX & X HARPACTICOIDA (concluded), CYCLOPOIDA WITH 12 AUTOTYPIC PLATES BERGEN PUBLISHED BYTHE BERGEN MUSEUM SOLD BY ALB. CAMMERMEYERS'S FORLAG, CHRISTIANJA 1921 AN ACCOUNT OF THE CRUSTACEA OF NORWAY AN ACCOUNT OF THE CRUSTACEA OF NORWAY WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES BY G. 0. SARS PROFESSOR OF ZOOLOGY AT THE UNIVERSITY OF CHRISTIANIA VOL. VII COPEPODA SUPPLEMENT WITH 76 AUTOTYPIC PLATES BERGEN PUBLISHED BY THE BERGEN MUSEUM SOLD BY ALB. CAMMERMEYER'S FORLAG, CHRISTIANIA 1921 BERGEN, A/S JOHN GR1EGS BOKTRYKKERI OG N. NILSSEN & S0N PREFACE By the present Volume my Account of the 3 leading divisions of Copepoda, the Calanoida, Harpacticoida and Cyclopoida is finaly concluded. Yet there still remains a considerable bulk of Copepoda of a more or less pro- nouncedly parasitic nature, the most familiar of which are the genuine Fish- parasites, the Caligoida and the Lernceoida. These 2 divisions have however recently been so carefully treated of in the excellent and beautifully illustrated work of Th. & A. Scott (British parasitic Copepoda), that a renewed account of these forms appears to be less needed. On the other hand, 2 other anomalous divisions of Copepoda, likewise in some measure parasitic in habits, but not included in the above mentioned work, viz., the Monstrilloida and the Notodelphyoida, may be more worthy of a careful reexamination. It is indeedmy purpose in the next Volume now in preparation to give an exhaus- tive account of the Norwegian forms referable to these 2 interesting divisions, which in some .respects show relations partly to the free-living Copepoda, partly to the true parasites. I take the occasion again to express my most sincere thanks to the Direction of the Bergen Museum for the interest it has shown for my work and for the kindness in giving me an opportunity of still continuing it, in spite of the many obstacles which in these difficult times have arisen against the printing and publication. G. O. Sars. 93 75. Danielssenia robusta, G. O. Sars, n. sp. (PI. LXIV). Specific Characters. Female. Body comparatively robust, with the anterior division rather dilated and evenly vaulted above. Cephalic segment nearly as long as the 3 succeeding segments combined, and produced in front to a thin rostral plate obtusely rounded and somewhat defexed at the end. Epimeral plates of the 3 succeeding segments somewhat produced behind. Last trunkal segment very small. Urosome comparatively short, scarcely attaining half the length of the anterior division, and only very slightly tapered behind, its segments minutely denticulate at the hind edges; genital segment about the length of the 2 succeeding segments combined; last segment some- what smaller than the preceding one. Caudal rami very short, being scarcely half as long as they are broad; apical setae rather slender. Anterior antennae, as in the type species, only composed of 4 joints, and exhibiting a very similar structure and armature. Posterior antennae likewise very similar. Man- dibular palp with the basal part considerably expanded, and carrying along the hind edge of the projecting inner part 4 strong ciliated setae. Maxillae and maxillepeds scarcely differing in their structure from these parts in the other species. Natatory legs likewise built on the same type, though differing in the inner ramtis being somewhat more produced. Last pair of legs com- paratively of smaller size than in the other 2 Norwegian species, with the distal joint less broad and having the innermost seta spiniform; inner expansion of proximal joint far less produced, scarcely extending beyond the distal joint, and only provided with 3 marginal setae. Colour whitish grey, with a fainte rosy tinge. Length of adult female about 1 mm. Remarks. The present form is nearly allied to the other 2 Norwegian species, through more robust in shape, and also of larger size than any of them. The structure of the several appendages agrees on the wole rather closely with that found in the said species, except the last pair of legs, which are of much smaller size and also conspicuously different in shape. Occurrence. Several specimens of this large species, most of them of the female sex, were found at Ris0r in depths ranging form 30 to 60 fathoms, coarse muddy sand. 14 - Crustacea. 94 Gen. Psammis, G. O. Sars. Remarks. This genus was established by the present author in the year 1911, to include a single species of which at that time only 2 female specimens had come under my notice. I have subsequently had an oppor- tunity of examining also a fully adult male specimen, and, as the sexual diffe- rences in this form are rather striking, both as regards the outward appearance and the structure of some of the appendages, I have found it advisable to give below a full description of the specimen accompanied by figures of the whole animal and of some of the structural details. 76. Psammis Songisetosa, G. O. Sars. (PI. LXV). See Vol. V, p. 339, PI, CCXXV. Specific Characters. Male. Body considerably more slender than in female and gradually tapered behind. Cephalic segment about occupying half the length of the anterior division, and provided in front with a well-defined and rather prominent rostral plate of regularly oval form, with 2 delicate sen- sory hairs on each side. Urosome about equalling in length 3 A of the anterior division, and composed of 5 well defined segments, the 4 anterior of which are of about equal size; last segment considerably smaller and somewhat widening distally, with the anal opercle inconspicuous. Caudal rami consider- ably divergent, with the apical setae greatly prolonged. Anterior antennae very strongly built and conspicuously hinged, being apparently composed of 7 joints, the penultimate of which is strongly inflated, almost globose in form; terminal joint narrow unguiform and very mobile, admitting of being impinged against the anterior face of the preceding joint, both together forming a very powerful grasping organ. Posterior antennae and oral parts scarcely different from those in female. 1st pair of legs also rather similar, only differing in the shape of the spine issuing from the inner corner of the 2nd basal joint, this spine being not, as in the female, straight, but distinctly curved inwards. 2nd pair of legs with the inner ramus conspicuously transformed, each of the joints being produced at the end outside to a well defined acuminate process, that of the middle joint being much the largest, mucroniform, and extending almost to the end of the terminal joint. The 2 succeeding pairs of legs of the very same structure as in the female. Last pair of legs however very different, the distal joint being not, as in the female confluent with the proximal one, but 95^ well defined, rounded in form and carrying 4 slender marginal spines; inner expansion of proximal joint comparatively small, scarcely extending beyond the middle of the distal joint, and only provided with 2 spines of somewhat unequal length. Length of the specimen examined 0.72 mm. Remarks. The identification of the above-described form as the male of P. longisetosa cannot be contested, though some of the characters, especi- ally the structure of the last pair of legs, are not in accordance with the diagnosis previously given of the genus. Occurrence. The above-described male specimen was, like the female, found at Farsund. I have not met with this form in any other locality on the Norwegian coast. Gen. Argestes, G. O. Sars. Remarks. This is another genus originally founded only on a single species, A. tnollis G. O. Sars, found at Bukken, south west coast of Norway. A slender Copepod recently found off the southern coast seems, according to the structural details, to be referable to the same genus, though in its outward appearance it looks rather different from the type species. A description of this form is given below. 77. Argestes tenuis, G. O. Sars, n. sp. (PI. LXV1I). Specific Characters. Female. Body slender and narrow, v/ith the anterior division only slightly dilated, and the integuments very thin and pellucid. Cephalic segment somewhat exceeding in length the 2 succeeding segments combined, and without any distinctly defined rostral projection. Lateral parts of the 3 succeeding segments rounded off; last trunkal segment smaller than the preceding one. Urosome narrow cylindrical in form, and nearly attaining the length of the anterior division, its segments very finely den- ticulate at the hind edges, and clothed laterally with delicate adpressed spikes; genital segment comparatively large and conspicuously protuberant below in its anterior part; last segment somewhat larger than the preceding segment and quadrangular in outline, anal opercle very broad and perfectly smooth at the edge. Caudal rami about the length of the anal segment and narrow linear in form, with all the setae issuing from the slightly thickened extremity, the 2 middle apical seta? very slender. Anterior antennas nearly as long as 96 the cephalic segment and, as in the type species, composed of 7 well defined joints clothed with rather strong finely denticulated setae; the first 2 joints much larger than the others, terminal part, composed of the 3 outermost joints, about half the length of the proximal one, with the last joint the largest. Posterior antennae comparatively feeble in structure, with the outer ramus rudimentary. Mandibular palp without any distinctly defined outer ramus, its place being occupied by a simple seta. Maxillae and maxillipeds scarcely different from those in the type species. Natatory legs, as in that species, well developed, with both rami distinctly 3-articulate, being in 1st pair of about equal size, in the succeeding pairs a little unequal, though less so than in the type species. Last pair of legs with the distal joint considerably pro- duced and of narrow linear form, carrying 5 comparatively small marginal setae, the proximal one of the outer edge rather remote from the others; proximal joint quite short, and not at all expanded inside, with only 2 small juxtaposed bristles on the hind margin. Male somewhat smaller than female, and resembling it in the general shape of the body, being however easily recognised by the more strongly built and distinctly hinged anterior antennae. Colour whitish pelluid. Length of adult female 0.83 mm. Remarks. In its outward appearance this Copepod bears a general resemblance to the form described above as Leptocletodes debilis, exhibiting a rather similar slender and narrow shape of the body and a similar week consistency of the integuments. On a closer examination, however, the structure of the several appendages, and more particularly that of the natatory legs, is found to be esentially different, and on the whole perfectly agreeing with that in Argestes mollis, with which species it accordingly must be assosiated in the same genus. Occurrence. I have only met with this form in a single locality on the Norwegian coast, viz., at Riser, where some few specimens were taken from the considerable depth of 60 80 fathoms, muddy bottom. Gen. Euterpina, Norman, 1903. Syn: Euterpe, Glaus (not Swainson). Generic Characters. Body subpyriform in shape, with no very sharply marked limit between the anterior and posterior divisions. Cephalic segment large and acutely produced in front. Urosome comparatively small, with the 97 caudal rami not much produced, setae of the latter reduced in number. Anterior antennas in female of moderate size, and clothed with scattered simple setae; those in male much larger and very strongly hinged. Posterior antennas with the outer ramus well defined, though only composed of a single joint. Mandi- bles rather coarse, with the palp distinctly biramous. Maxillae without any distinctly defined exopodal and epipodal lobes. Anterior maxillipeds with 3 well defined setiferous lobes inside the basal part. Posterior maxillipeds ex- tremely slender and narrow. 1st pair of legs with both rami short, biarticulate' the 3 succeeding pairs with the rami distinctly 3-articulate, but of rather unequal size. Last pair of legs represented by two undivided juxtaposed plates, which in male are coalesced in the middle. Remarks. As the name Euterpe, originally assigned to this genus by Glaus, had been preoccupied in Entomology, the above slight change of the name has been proposed by the Canon Norman. The genus is somewhat allied to Tachidins, differing however in some particulars rather markedly, especially as regards the structure of the posterior maxillipeds and the 1st pair of legs. It comprises as yet only a single species, to be described below. 78. Euterpina acutifrons, (Dana). (PI. LXVIII). Haipacticus? acutifrons, Dana, Crustacea of the Un. St. Expedition, p. 1192, PI. 83, figs. 11 a b. Syn: Euterpe gracilis, Glaus. Specific Characters. Female. Body comparatively slender, with the anterior division conspicuously broader than the posterior and evenly vaulted above. Cephalic segment occupying about half the length of the anterior division, and gradually exserted in front to a greatly prominent rostral pro- minence, acute at the tip. Lateral parts of the succeeding segments not expanded. Last trunkal segment much smaller than the preceding one. Uro- some not nearly attaining half the length of the anterior division and rather narrow, tapered distally, with the segments minutely denticulated at the hind edges; genital segment about the length of the 2 succeeding segments combined and imperfectly subdivided beyond the middle; last segment scarcely shorter than the preceding one, with the anal opercle finely denticulated at the edge. Caudal rami only slightly longer than they are broad and not at all divergent, each ramus provided near the base with a small subdorsal bristle and at the transversely truncated extremity with 2 rather strong setae of unequal length. Anterior antennae about half as long as the cephalic segment and rather narrow, 98 being composed of 7 well defined joints not much different in size, the terminal one however rather smaller than the others. Posterior antennas with the basal part distinctly subdivided, terminal joint with the spines and setae rather slender; outer ramus provided with 4 stibequal ciliated setae. Posterior maxilliped with the hand scarcely at all dilated and about of same size and appearance as the basal joint, dactylus extremely slender, with scattered long hairs inside. 1st pair of legs rather small, and provided with the usual deflexed spine at the inner corner of the 2nd basal joint; rami of about equal size, with the distal joint somewhat larger than the proximal one. The 3 succeeding pairs of legs with the outer ramus rather strongly built and densely fringed outside with small spinules, spines attached to this ramus unusually coarse, 3 of them issuing close together from the end of the terminal joint; inner ramus shorter and much narrower than the outer. Last pair of legs consisting of 2 juxta- posed oblong quadrangular plates, contiguous at the base and fringed inside and at the end with short cilia, each plate having outside, at some distance from the base, a slender bristle and moreover 5 comparatively short and finely denticulated spines, one of them attached to the outer edge in about the middle, the other 4 to the transversely truncated end. Ovisac of moderate size and globular in form. Male of about same size as female, and not very different in the shape of the body. Anterior antennae however much more strongly built and pronouncedly hinged, being apparently only composed of 5 joints, the penulti- mate of which is very large and tumid, sub-pyriform in shape; terminal joint forming a slender and very mobile claw-like dactylus. Posterior antennae with one of the setas attached to the outer ramus much stronger than the others, almost claw-shaped. 1st pair of legs differing somewhat from those in the female in the shape of the inner ramus, the proximal joint of which is com- paratively more produced and forming with the distal one an abrupt geniculate bend. Last pair of legs rather unlike those in female, being represented by a single median plate, divided at the end by a short incision into 2 small lobules, each carrying 2 short spines. Genital lobes rather prominent, each armed with 2 coarse spines. Body in both sexes pellucid, without any conspicuous pigmentation. Eye in preserved specimens inconspicuous, but well observable in the living animal, and of a light red colour. Length of adult female reaching 0.67 mm. Remarks. This form has by most authors been recorded under the name Euterpe gracilis given to it by Glaus; but there cannot be any doubt 99 that Giesbrecht was right in identifying it with the species previously recorded by Dana as Harpacticus acutifrons. It is an easily recognisable form, dif- fering also markedly in habits from most other Harpacticoida, being a true pelagic animal. Occurrence. Some specimens of this widely distributed Copepod were found in a plankton-sample taken in the Skaggerak, about midways between the Norwegian coast and Skagen, and this occurrence may justify the reception of the present form within the Fauna of Norway. Distribution. North Sea (at Helgoland), Atlantic Ocean, Mediter- ranean, Indian Ocean. Fam. Clytemnestridae. Remarks. This family has recently been established by A. Scott, to include the genus Clyneninestra of Dana, which indeed in several points differs so markedly from the other Harpacticoida, that it scarcely can find its place in any of the other families of that division. No other genus referable to this family is as yet known. Gen. Clytemnestra, Dana, 1852. Syn : Goniopelte, Glaus. Goniopsyllus, Brady. Generic Characters. Body more or less slender, tapering distally, with the anterior division conspicuously depressed, its segments, except the last one, being lamellarly expanded and projecting laterally to prominent triangular lappets. Cephalic segment very large, clypeiform, and produced in front to a well defined rostral prominence. Urosome much narrower than the anterior division, and sub-cylindrical in form. Caudal rami comparatively short, with the apical setae much reduced in size. Anterior antennae slender and attenuated, composed of 7 or 8 joints; those in male imperfectly hinged. Posterior antennae with the outer ramus replaced by one or 2 setae. Mandibles very small, with the masticatory part narrowly exserted and the palp obsolete. Maxillae much reduced. Anterior maxillipeds with only a single setiferous lobe inside the basal part Posterior maxillipeds very slender, with the basal part 100 much produced; hand in female scarcely at all dilated, with the dactylus very small, in male somewhat more strongly developed. Natatory legs slender, with the inner ramus in all of them 3-articulate and longer than the outer, the later in 1st pair uniarticulate, in the succeeding pairs 3-articulate. Last pair of legs forming each a narrow biarticulate stem extended somewhat laterally. Remarks. The present genus was established by Dana in the year 1852, to include a peculiar Copepod found in the Pacific. Neither Glaus nor Brady recognised Dana's genus, and the generic names proposed by these authors, Goniopelte and Goniopsyllits, are indeed only synonyms of that genus. The species of the present genus are readily recognised by the peculiar flat- tened and laciniate shape of the anterior part of the body, caused by the lamellar expansions of the segments, as also by the very short caudal setae. Of the structural details may be noted the poor development of the oral parts, and the rather anomalous structure of the legs, especially that of the 1st and last pairs. The genus comprises as yet only 2 nearly-allied species, both truly pelagic in habits. One of these species has proved to be referable to the Fauna of Norway, and will be described below. 79. Clytemnestra scutellata, Dana. (PI. LXIX). Clytemnestra scutellata, Dana, Crustacea of the U. S. Explor. Expedition, p, 1194, PI. 83. Syn : Goniopelte gracilis, Glaus. Specific Characters. Female. Body moderately slender and rapidly tapered behind, with the anterior division conspicuously expanded and some- what flattened. Cephalic segment very large and broad, fully occupying half the length of the anterior division, with the postero-lateral corners triangularly produced; rostral projection rather prominent and obtusely pointed at the end. The 3 succeeding segments successively somewhat diminishing in size, each produced laterally to a prominent triangular lappet pointing obliquely back- wards. Last trunkal segment very small, without any lateral expansions. Uro- some scarcely attaining half the length of the anterior division and of narrow cylindrical form, though a little tapering in its outermost part; genital segment comparatively large and not subdivided in the middle; last segment about the size of the preceding one and transversely truncated at the end, with the anal opercle very small. Caudal rami fully twice as long as they are broad and somewhat incurved, with the outer distal corner conically produced; outer edge with 2 successive slender spines near the base and a short seta close to the 101 end; dorsal seta likewise attached near the end; apical setae 3 in number, the innermost very small, the middle one the longest, though only slightly exceeding the ramus in length. Anterior antennae very slender and attenuated, exceeding somewhat in length the cephalic segment, and composed of 8 well defined joints clothed with scattered comparatively short setae, each antenna carrying more- over 5 well developed aesthetasks, one attached in the middle of the 4th joint, 2 to the end of the 5th joint, and 2 to the tip of the very slender terminal joint. Posterior antennae with the basal part distinctly subdivided, terminal joint comparatively narrow, with the number of spines and setae reduced; outer ramus replaced by 2 juxtaposed ciliated setae of equal length. 1st pair of legs wanting the usual spine inside the 2nd basal joint; outer ramus imperfectly developed, only consisting of a single narrow linear joint, not even extending to the middle of the 2nd joint of the inner, and without any spines outside. The 3 succeeding pairs of legs^with the 2nd basal joint bent outwards at an angle with the 1st; both rami distinctly triarticulate and very narrow, the inner one being the longer; 1st joint of outer ramus nearly as long as the other 2 combined and in 2nd pair wanting the usual spine outside. Last pair of legs with the distal joint about 3 times as long as the proximal one and very narrow, carrying 6 slender marginal setae, 2 on the outer edge and 4 on the apex. Colour (according to Giesbrecht) whitish grey, with a slight rosy tinge. Length of the specimen examined 1.24 mm. Remarks. This is the species first described, and may accordingly be considered as the type of the present genus. It is closely allied to the form recorded by Brady from the Challenger Expedition under the name of Gonio- psyllus restrains, which, as stated by Giesbrecht, is another species of the same genus, differing from the one here described in the comparatively shorter caudal rami, as also somewhat in the structure of the antennae. In Brady's species the anterior ones are only composed of 7 joints, and the posterior one have only a single seta in the place of the outer ramus. Occurrence. A solitary female specimen of the present form was found in a sample taken, many years ago, in the upper part of the Christiania Fjord. This is the only instance of the occurrence of the present form off the coasts of Norway. I have never met with it subsequently. Distribution. Irish Sea, Atlantic Ocean, Mediterranean, Gulf of Guinea, Indian and Pacific Oceans. 15 Crustacea. CYCLOPOIDA. Gnathostoma, Fam. Cyclopinidae. Gen. Cyclopina, Glaus. Remarks. On a careful examination of numerous specimens of Cyclo- pina taken in many different places of our coast, I am led to the conclusion that several nearly-allied species have hitherto been confounded, some of them agreeing more closely with C. gracilis Glaus, some others with C. longicornis Boeck. The supposed variability in the 2 said species of the caudal rami I am now not prepared to admit. In all other known Copepoda these appen- dages exhibit a perfectly constant appearance both as to form and relative size, and indeed furnish one of the best and most reliable characters for distinguishing nearly allied species. This I believe also applies to the species of the genus Cyclopina. If therefore any peculiarity in the structure of these appendages is found, this ought in my opinion to be regarded as an infallible indication of specific difference, unless quite gradual transitions could be stated to occur. But, according to my recent investigations, such transitions do not in reality exist. I have already in Vol. VI recorded 2 species closely agreeing with C. gracilis in the structure of the several appendages, but easily recognis- able by the different appearance of the caudal rami, and I now propose to distinguish 4 other species, 2 of which are likewise closely allied to that species, whereas the other 2 approash nearest to C. longicornis. 80. Cyclopina norvegica, Boeck. (PI. LXIX, Fig. 1). Cyclopina norvegica, Boeck, Oversigt over de ved Norges Kyster iagtlagne Copepoder. Chr. Vid. Selsk. Forhandl. 1864, p. 247. Syn: Cyclops salinns, Brady. Specific Characters. Female. Body resembling in shape that of C. gracilis, but of rather inferior size, and having the anterior division more 103 regularly oval in form, with the cephalic segment less contracted in front. Tail comparatively slender, with the genital segment about as long as the 3 suc- ceeding segments combined and very slightly dilated in its anterior part. Caudal rami much shorter than in C. gracilis, only slightly exceeding in length the anal segment, and scarcely more than 3 times as long as they are broad; seta of outer edge attached near the middle; innermost apical seta about twice as long as the outermost. Antennae, oral parts, and natatory legs of a structure very similar to that in C. gracilis. Last pair of legs likewise built on the same type as in that species, though, on a closer comparison, exhibiting slight differences in their form, the distal joint being more elongate and more strongly constricted at the base, with the outer apical spine fully twice as long as the inner. Ovisacs of moderate size and closely appressed to the sides of the tail. Colour uniformly whitish grey. Length of adult female scarcely exceeding 0.50 mm. Remarks. The above described form is unquestionably that briefly announced by Boeck under the name of C. norvegica and also observed by several other authors, but regarded by them as identical with C. gracilis Claus. The latter species, originally described from the Mediterranean, has also been found by the present author on the Norwegian coast, and is figured in Vol. VI, PI. IV. Occurrence. This is a pronouncedly littoral form, being only found close to the shores and frequently occurring in shallow pools left by the tide. I have met with it in many places, both of our southern and westeren coasts. Distribution. British Isles, bay of Kiel, coast of France, Polar Sea. 81. Cyclopina brachystylis, n. sp. (PI. LXX, Fig. 2). Specific Characters. Female. Body comparatively short and stout, with the anterior division broadly oval in form, greatest width occurring some- what behind the middle. Tail comparatively less slender than in the preceding species, with the genital segment scarcely longer than the 2 succeeding ones combined. Caudal rami very short, not even attaining the length of the anal segment and only sligthly longer than they are broad; seta of outer edge attached about in the middle; apical setae of moderate length, the innermost one a little longer than the outermost. Anterior antennae comparatively short and, as in the preceding species, only composed of 10 joints, the 6th of which is much the longest, though scarcely attaining the length of the 4 succeeding 104 joints combined. Last pair of legs resembling somewhat in shape those in the preceding species, but with the proximal joint comparatively less broad and the apical spines more unequal in length. Ovisacs very small and closely appressed to the sides of the tail. Colour, as stated in a specimen recently taken at Sandefjord, pale yellowish grey with slight darker yellow shadows; anterior antennae partly tinged with orange. Length of adult female scarcely exceeding 0.56 mm. Remarks. By the very short caudal rami this form has a certain resemblance to C. Schneideri Scott (= C. brevifnrca G. O. Sars), and may indeed on this account easely be confounded with that species. It is however much inferior in size, and moreover well distinguished by the structure of the anterior antennae, which are comparatively shorter and, as in the preceding species, only composed of 10 joints, whereas these antennae in C. Schneideri are distinctly 12-articulate. The general form of the body also is somewhat different in the two species. Occurrence. I have met with this form in several places, both on the southern and western coast of our country, and northwards at least to the Trondhjem Fjord (Bejan). It is found in moderate depths, from 10 to 50 fathoms, but never in the littoral zone. 82. Cyclopina littoralis, Brady. (PI. LXIX, fig. 3). Cyclopina littoralis, Brady, Nat. Hist. Trans. Northumberland and Durham, Vol. IV, p. 429. PI. XVII, figs 9-14. Specific Characters. Female. Body comparatively slender, resembling in shape that of C. longicornis, but rather inferior in size. Tail, including the caudal rami, about the length of the cephalic segment and sligthly attenuated behind. Caudal rami much shorter than in C, longicornis, not nearly attaining the length of the 2 preceding segments combined, and scarcely more than 4 times as long as they are broad; seta of outer edge attached about in the middle; innermost apical seta more than twice as long as the outermost. Antennas, oral parts, and natatory legs of a structure very similar to that in C. longicornis. Last pair of legs, as in that species, composed of 3 well defined joints, the middle one rather large, with the outer corner conically produced and tipped with a long seta; terminal joint comparatively small and 105 broadly rounded at the end, which carries 4 ciliated setse, the innermost of which is the shortest. Ovisacs of moderate size and slightly divergent. Body of a clear whitish colour and partly ornamented with a fine rosy pigment. 1 ) Length of adult female scarcely exceeding 0.65 mm. Remarks. It is possible that the form observed by Boeck more pro- perly may be referable to the present species. In this cas should consequently in strict law the form described in Vol. VI as C. longicornis Boeck have a new name. I think however it may be allowed to retain both these names in the sense here proposed. The 2 species are certainly very nearly allied, but may at once be distinguished by the different length of the caudal rami. I have failed to detect any transition in this respect. Occurrence. The species occurs along our whole southern and western coast, from the Christiania Fjord at least to Molde. It is always found close to the shores among algse and sometimes, as stated by Brady, even in pools left by the tide, never, as is the cas with C. longicornis, at any consider- able depth. Distribution. British Isles (Brady), Mediterranean (Giesbrecht). 83. Cyclopina dilatata, n. sp. (PI. LXX, fig. 1). Specific Characters. Female. Body rather short and stout, with the anterior division unusually dilated and, viewed dorsally, of rounded oval form. Cephalic segment very large, about twice as long as the remaining part of the trunk, and quite evenly rounded in front. Tail comparatively narrow, and occupying nearly half the length of the body; genital segment about equalling in length the 2 succeeding segments combined and sligtly widening in front. Caudal rami resembling in shape and relative length those in C. littoralis; seta of outer edge, however, attached somewhat in front of the middle. Anterior antennae comparatively shorter and less attenuated than in the said species, but composed of 19 well defined joints clothed with comparatively short setae. Posterior antennae, oral parts, and natatory legs apparently of a structure similar to that in C. littoralis. Last pair of legs however, though built on the same type, of a somewhat different appearance, the terminal joint J ) The colour as signed (in Vol. VI) to C. longicornis, applies in reality only to the present species. C. longicornis is of a much paler hue. 106 being oi rather larger size, fully as long as the other 2 combined, and obliquely rounded at the end. Ovisacs wanting in the specimens examined. Colour of the living animal not yet ascertained. Length of adult female 0.56 mm. Remarks. This form also is nearly allied to C. longicorni-s, but may at once be distinguished both from this and the other known species by the unusually broad and expanded anterior division of the body. The structure of the anterior antennae and of the last pair of legs is also somewhat different. Occurrence. Two female specimens only of this form have as yet come under my notice. They were both found in a sample taken at Kors- havn from a depth of about 40 fathoms. Fam. Cyclopidae. Gen. Euryte, Philippi. 84. Euryte minor, Scott. (PI. LXX, fig. 2). Kiuyie longicauda, var. minor, Scott, Twenty-third Annual Report of the Fishery Board for Scotland, Part III, p. 143, PI. X, figs 13, 14. Specific Characters. Female. Very like E. longicauda Philippi, but rather inferior in size and of somewhat more slender form of the body. An- terior division, seen dorsally, rounded oval in outline, with the cephalic segment very large and broadly rounded in front. Rostrum strong and abruptly recurved. Tail including the last trunkal segment, occupying about half the length of the body; genital segment somewhat less broad than in E. longicauda, but, as in that species, armed on each side in the middle with a strong dentiform projection curving backwards; anal segment scarcely longer than the preceding one. Caudal rami resembling in shape those in E. longicauda, being rather narrow and elongated, diverging somewhat in their outer part. Antennas oral parts, and legs of a structure very similar to that in the type species. Ovisacs narrow oblong in form, and somewhat less strongly divergent than in E. longicauda. Male of smaller size than female and a little more slender of form, with the cephalic segment less broad in front and the tail composed of 107 5 well defined segments. Genital segment considerably dilated, almost quadrate in form, and, as a rule, containing on each side an oblong oval spermatophore. Caudal rami comparatively shorter than in female. Anterior antennae very strongly hinged. Colour whitish grey, with a very slight pale yellow tinge. Length of adult female scarcely attaining 1 mm.; that of male 0.78 mm. Remarks. This form was considered by Scott and also by myself as only a variety of E. longicauda. I am however now of opinion that it should more properly be regarded as a separate, though closely allied species. Occurrence. I have met with this form in many different places of our coast, and have always found its characters constant. It is, unlike E. longi- couda, a true deep-water form, occurring in depths ranging from 20 to 50 fathoms, never in the littoral zone. Distribution. Scottish coast (Scott). Siphonostoma. Fam. Ascomyzontidae. Gen. Rhynchomyzon, Giesbr. 85. Rhynchomyzon falco, Giesbr. (PI. LXXI). R/iync//otnyzon falco, Giesbrecht, Die Asterocheriden des Golfes von Neapel, p. 102, PI. 5, figs. 2840. Specific Characters. Male. Body comparatively robuste, with the anterior division rather broad in the middle and somewhat depressed. Cephalic segment very large, about twice as long as the remaining part of the trunk, and, seen dorsally, triangular in outline, being gradually contracted anteriorly, with the extremity narrowly truncated; lateral corners slightly produced, biden- tate. Rostrum very strong, falciform, and curved downwards. The 3 suc- ceeding segments, like the cephalic segment, somewhat raised dorsally at the hind edge, and having the lateral corners produced to triangular recurved lappets. Last trunkal segment, as usual, much smaller than the preceding ones, 108 and slightly produced on each side. Tail comparatively short, not attaining half the length of the anterior division, and composed of 5 segments, the 1st (genital) of which is broadly quadrangular in form and provided at the hind corners with 2 juxtaposed setae of unequal length; each of the 2 succeeding segments produced laterally to acute triangular lappets curved backwards; the last 2 segments firmly connected and without any lateral projections. Caudal rami comparatively short, being only slightly longer than they are broad, and somewhat divergent; apical setae not much elongated. Anterior antennae not nearly attaining the length of the cephalic segment, and scarcely at all hinged, being composed of 17 joints, the 1st of which is much the largest, the 9th imperfectly subdivided in the middle; proximal half of the antenna somewhat thickened and clothed in front with scattered rather strong spiniform setae, carrying moreover 8 very slender recurved aesthetasks; penultimate joint with a single such aesthetask behind near the end. Posterior antennae resembling in structure those in the 2 other known species. Oral cone, as in R. pur- piirotinctum, very massive and prominent, but not prolonged in any true siphonal tube. Mandibles rather strong, pronouncedly cultriform, and finely denticulated inside the extremity; palp very small. Maxillae, maxillipeds and natatory legs of the usual structure. Last pair of legs extremely small, biarticulate. Colour of the living animal not yet ascertained. Length of the specimen examined 1.25 mm. Remarks. I think I am right in determining the above-described remark- able form as the hitherto unknown male of R. falco Giesbrecht. It may easily be recognised from the other 2 Norwegian species described in Vol. VI by the robust form of the body, by the strongly marked armature of the seg- ments, and by the comparatively short caudal rami. Occurrence. The solitary specimen obtained was found in a sample taken at Ris0r from a depth of about 30 fathoms. Distribution. Gulf of Naples (Giesbrecht). 109 Fam. Acontiophoridae. Gen. Acontiophorus, Brady. 86. Acontiophorus ornatus, Brady. (PI. LXXII). Asconiyzon onwtnm. Brady & Robertson, British Assoc. Report p. 197. Specific Characters. Female. Body on the whole of a more robust appearance than in A. scutatus, with the anterior division broadly oval in form and somewhat depressed, greatest width considerably exceeding half the length and occurring behind the middle. Cephalic segment very large, nearly twice the length of the trunk, and narrowly rounded in front, lateral corners slightly produced. The 3 succeeding segments comparatively broad, with the epimeral plates somewhat expanded an distinctly angular behind. Last trunkal segment very small. Tail slightly exceeding in length V?, of the anterior division; genital segment about occupying half the length of the tail and almost of equal width ^throughout, lateral corners of this and the succeeding segment acutely produced behind. Caudal rami comparatively short, being scarcely longer than they are broad; apical setae well developed and partly finely plumose. Anterior antennae much more slender and elongated than in A. scutatus, and composed of 16 well defined joints, the 3rd of yhich is much the largest; proximal part of the antenna only slightly dilated and clothed with strong partly ciliated setae. Posterior antennae likewise comparatively more slender than in the type species, though of rather similar structure. Siphonal tube scarcely extending beyond the anterior division of the body. Oral appendages and natatory legs on the whole built on the same type as in A. scutatus. Last pair of legs, however, of comparatively larger size, with the proximal joint very broad, lamellar, and irregularly indented behind; distal joint oval in form and provided with 5 ciliated setae of about equal length. Colour of the living animal not yet ascertained. Length of adult female 1.03 mm. Remarks. This form was at first recorded by Brady and Robertson under the name of Asconiyzon ornatus, and was subsequently redescribed and figured by the first-named author in his well-known Monograph as Acontio- phorus armatus. As however the specific name ornatus is the older one; it must be retained for the present form. The differences between this species and A. scutatus are very pronounced, and at first I therefore believed them to 16 - Crustacea 110 be of generic value. I am however now disposed to include both species in the same genus. Occurrence. A solitary female specimen only of this pretty form has as yet come under my notice. It was found in a sample taken at Riser in about the same place, where Rhyncomyzon falco occurred. Distribution. British Isles (Brady), Mediterranean (Giesbrecht). Poecilostoma. Fam. Lichomolgidae. Gen. Hermannella, Canu. 87. Hermannella dubia, n. sp. (PI. LXXIII, fig. 1). Specific Characters. Male. Anterior division of body rather broad, sub-depressed, seen dorsally broadly oval in outline, with the greatest width equalling -1% of the length and occurring in front of the middle. Cephalic segment very large, fully twice as long at the 3 succeeding segments com- bined, and evenly rounded in front, exhibiting behind the middle a well- marked transverse suture. Last trunkal segment very small. Tail about equalling in length 2 /.-i of the anterior division, and composed of 5 well defined seg- ments, the 1st of which (the genital segment) is very large and expanded, almost circular in outline, exhibiting on each side a roomy chamber for the reception of the spermatophores; the remaining segments narrow cylindrical in form, the last being the largest. Caudal rami about 3 times as long as they are broad and scarcely at all divergent; seta of outer edge attached in the middle; apical setae partly brocket! in the specimen examined, but appar- ently normal. Anterior antennae less slender than in the other known species, scarcely exceeding half the length of the cephalic segment, and only composed of 6 joints. Posterior antennae not very strong, and composed of 4 well-defined joints, the 2nd of which is the largest; 3rd joint armed at the end anteriorly with a hook-like spine accompanied proximally by 2 small bristles; last joint of about same size and provided at the tin with 4 curved claws, 2 of which JJi are distinctly jointed in the middle; outside the latter a slender curved seta is attached. Maxillae with the masticatory lappet fusiform in shape and exserted to a very long and narrow setiform lash, inner edge armed with about 8 strong curved denticles, outer edge ciliated; palp of the usual appearance. Anterior maxillipeds with the distal joint gradually tapered and provided inside with a stout spine, terminal proces only slightly curved and armed outside with 4 5 unusually slender spinules. Posterior maxillipeds exhibiting the structure usual for male specimens. The 3 anterior pairs of natatory legs on the whole of normal appearance, with the rami eomparatively broad and subequal in size; 4th pair however distinguished by the want of the outer-edge spines on the outer ramus, inner ramus scarcely narrower than the outer and having 2 seta? inside the midle joint, terminal joint with 3 unusually slender spines at the end and with the inner edge smooth. Last pair of legs with the free joint narrow linear in form and carrying at the tip a slender spine and a some- what shorter seta, inner distal corner produced to a well-marked dentiform projection. Colour of the living animal not yet ascertained. Length of the specimen examined 0.70 mm. Remarks. The above-described form cannot be referred to any of the hitherto known species, differing, as it does, conspicuously by the comparatively short 6-articulate anterior antennae, as also by the structure of the posterior antennae. and that of the 4th pair of legs. In the broadly expanded anterior division of the body it somewhat resembles H. valida G. O. Sars, but is otherwise very different from that species Occurrence. The solitary male specimen obtained was found in a sample taken by Mr. Kjasr at Dr0bak from a depth of about 50 fathoms. Gen. Lichomolgella, G. O. Sars. 88. Lichomolgella pusilla, G. O. Sars. (PI. LXXIII, fig. 2). See: Vol. VI, p. 216, Pi. CXVIII, fig. 1. Remarks. This dwarfed form has been described and figured in Vol. VI from a solitary specimen taken at Skutesnaes, S. W. coast of Norway. On the accompanying plate I give new habitus-figures with some details of another specimen obtained on the south coast, at Lillesand. As seen from the figure, the lateral view of the body is rather characteristic by the unusually deep 112 and boldly vaulted cephalic segment giving the animal in that situation a very extraneous appearance. The specimen, though fully adult, did not exceed a length of 0.40 mm. Gen. Pseudomolgus, G. O. Sars. 89. Pseudomolgus arenicola, Brady. (PI. LXXIV). Lichomolgus arenicoltis. Brady, Alonogr. of British Copepoda, Part III, p, 46, PI, LXXXVIII, figs 1-7. Specific Characters, Female. General form of body very like that in P. leptostylis G. O. Sars 1 ), though perhaps a little less slender, with the anterior division more regularly oval in outline, the greatest width occurring in the middle. Head very distinctly defined from the 1st trunkal segment and narrowly truncated at the extremity. Last trunkal segment remarkably narrow and elongated. Tail about equalling in length the head and 1st trunkal segment^combined; genital segment fusiform in shape and distinctly subdivided in the middle by a transverse dorsal suture; anal segment only slightly longer than the preceding segment. Caudal rami much shorter than in P. leptostylis, not nearly attaining the length of the 2 preceding segments combined, and about of equal width throughout. Anterior antennas rather slender and, as in the 2 other species, composed of 7 joints, the somewhat oblique suture between the last 2 joint being distinctly marked. Posterior antennae very powerful, and agreeing both in form and armature with those in P. leptostylis. Anterior lip deeply insinuated in the middle. Maxillae with the 2 proximal denticles of the principal masticatory lappet somewhat lamellar in shape, their inner sharpened edge being divided into 3 or 4 fine spinules; palp of a somewhat irregular form, and having in the middle of the rounded extremity a well-marked narrow incision. Maxillipeds and legs almost exactly as in P. leptostylis. Body semipelluced, of a uniform whitish grey colour, with darker translucent ovaria. Eye well observable, with light reddish pigment. Length of the specimen examined 1.60 mm. Remarks. I cannot doubt that the above-described form is identical with the British species recorded by Brady and by Scott, though the description and figures given by those authors do not fully agree with those here given. The species is indeed still more closely, allied to P. leptostylis than I had See Vol. VI, p. 182, PI. GUI. formerly supposed by consulting the statements given by the said authors. Yet the species may at once be distinguished both from this and the other species (P. dilatatus) by the much shorter and stouter caudal rami. Occurrence. -- A solitary fully adult female specimen of this form was taken last summer at Hvaler, outside the Christiania Fjord, from a depth of about 10 fathoms. Distribution. British Isles (Brady, Scott). Fam. Sapphirinidae. Gen. Sapphirina, Thompson, 1829. Generic Characters. Body more or less conspicuously depressed and rather milike in the two sexes, that of male much broader than in female and blade-like, with the epimeral plates of both the anterior and posterior divisions lamellarly expanded, exhibiting moreover, in the living animal, a beautiful iridescent or opaline lustre. Head generally well defined from the 1st trunkal segment, and provided in front with 2 closely set cuticular lenses (conspicilla), behind which, as in Corycceus, at some distance 2 rod-like, pigmented strings occur, each terminating in a highly refractive body. 1 ) Tail much narrower in female than in male, and in both sexes composed of 5 well defined seg- ments. Caudal rami blade-like, with the marginal setae very small. Anterior antennae alike in the two sexes, and rather short, with the number of joints somewhat reduced. Posterior antennae distinctly prehensile, terminating in a short and stout claw. Oral parts built on the very same type as in the Lichomolgidce. Natatory legs well developed and more or less incurved, with both rami 3-articulate. Last pair of legs very small, uniarticulate, extended laterally. Remarks. This genus was established by I. V. Thompson as early as the year 1829, when our knowledge of the marine Copepoda was still very imperfect. The species observed by that zoologist (S. indicator) cannot be identified; but it is evident that he has had before him male specimens of some species belonging to the present genus, the brillant iridescence of their bodies having at once attracted his attention. The genus comprises numerous * !) As to the significance of this apparatus, 1 may refer to the note given in Vol. VI, p. 195, 114 species, chiefly occurring in the equatorial parts of the Oceans, though some- times by currents thrown more or less out of their true home. They are all pronouncedly pelagic animals, being as a rule met with in the open sea, near the surface of the water. As is the case with the other poecilostomous Cyclopoida, they are semiparasitic in habits, the females being at times found within the pallial cavity of various pelagic Tunicata (Salpae, Pyrosoma etc.). More generally however they are taken free in the sea, and this is always the case with the males. 90. Sapphirina iris, Dana. (PI. LXXV & LXXVI). Sapphirina iris, Dana, United States Explor. Expedition, Crustacea, p. 1239, PI. 87, figs. 1 a d Syn: Sapphirina salpip, Glaus. gemma. Brady (not Dana). Specific Characters. Female. Body elongate, gradually tapered behind, with all the segments sharply marked off from each other. Head defined from the 1st trunkal segment by a distinct, somewhat flexuous suture, and obtusely rounded in front; conspicilla well marked and closely approximate. Epimeral plates of the 3 middle trunkal segments distinctly prominent and obtuse-angular behind. Last trunkal segment much smaller than the preceding ones, but well defined. Tail rather narrow, exceeding somewhat half the length of the anterior division, and composed of 5 sharply defined segments, the genital segment being distinctly subdivided in the middle; lateral corners of this and the 3 succeeding segments angular behind; anal segment exceeding in size the preceding segment and quadrangular in form. Caudal rami rather large, attaining the length of the 2 preceding segments combined, and oblong oval in outline, with the inner edge much more curved than the outer and slightly angular at the end; seta of outer edge attached about in the middle, dorsal seta placed much nearer the extremity. Anterior antennae comparatively short and stout, gradually tapered distally, being composed of 5 joints, the 2nd of which is much the largest, occupying about half the length of the antenna. Posterior antennae rather strong, with the terminal part (composed of the last 2 joints) much shorter than the pre- ceding joint; apical claw short and stout, accompanied in front by 2 small bristles. Natatory legs with both rami well developed and of nearly equal size. Last pair of legs represented on each side by a small conical joint tipped with 2 unequal bristles. Ovisacs very long and narrow, almost cylindric in shape, and containing numerous ova. 115 Male rather unlike the female in its outward appearance, the body being very thin, blad-like, and broadly oval in outline, with the epimeral plates of all the segments, except the last trunkal and the last caudal one, lamellarly expanded and closely contiguous. Last trunkal segment very small and almost wholly concealed by the neighbooring segments. Last caudal segment likewise much smaller than in female. Conspicilla less sharply marked, and somewhat remote from the frontal margin. Posterior maxillipeds, as usual, more fully developed than in female, with the apical claw long and slender, Body of female (according to Giesbrecht) of a somewhat opaque yellowish grey colour, with pale reddish ovaria and ovisacs; that of male highly pellucid and, in the living state, brillantly iridescent. Length of female attaining 7.40 mm.; that of male 7.10 mm. Remarks. This is much the largest of the known species, and in the adult state it may thereby be easily recognised. In the general form of the body, however, as also in the structure of the several appendages it agrees very nearly with some of the other species, for instance S. gemma Dana, with which it was indeed identified by Brady. The S. salpce of Glaus is quite cer- tainly the present species. Occurrence. The present form, it is true, has not yet been recorded from the Norwegian coast, nor have I myself ever met with it here. I think, however, that it notwithstanding ought to be included in the Norwegian fauna as an occasional visitor. For it not seldom happens that shoals of Salpcp (S, runcinata, Chamissoj by heavy gales and currents are thrown from the open sea to certain points of our western coast, and, as the present copepod is a constant companion of Salpae, it is very likely to believe that it also in such cases has been associated with these pelagic Tunicata 1 ). The figures here given are drawn from specimens taken during the Monaco Expeditions in the North Atlantic Ocean. Distribution. - North and South Atlantic, Mediterranean, Indian Ocean, Pacific. '), My late father once witnessed such an influx of Salpae at Floro, where he at that time was settled as a pastor, and on a drawing made by him of a Salpa a parasit was indeed sketched within the pallial cavity, the relatively large size of this parasite supporting the suggestion that in fact it might have been a female of the present species of Sapphirina. INDEX Page. Acartia Hi latisetosa 16 Acartiidce 15 Acontioplioridu' 109 Acontioplioms 109 armatus 109 ornatns 109 sentatus 109 Anneira 57 dnbia 57 c.vilis 58 longicatuhita 63, 64 longiremis 59, 60 simplex 57 Argestes 95 mollis 95, 96 tennis 95 Ascoinyzoii 109 ornatum 109 Ascomyzontida? 107 Attheyella 55 Sc/itneili 55 Bathycalanus 11 Richardi 11 Bradya 42 armigera 42 congenera . 45 dilatata 42 f urea to 44 macrocha'ta 43 Scotti 42 si mu la ns 45 typica 42, 43, 45 Calanoida 2 Canthocamptidce 55 Canthocamptus 56 Schmeili 55 Cerviniidce 20 Cerviniopsis 20 Page. cUnncornis 20 Clctodes 75 abyssicola 81 irrasus 80 leptoslylis 77 longicaudatus 77, 78 moncnsis 80 per plexus ' 78 piisillns 76 Snrsi 75 Cletodida' 75 Cletomesochra 64 major 65 nana 66 rostra ta 67 Clytremnestta 89 scutellata 100 Clytemnestrid.ee 88 Cyclopida> 106 Cyclopina 102 brachystylis 103 dilatata 105 gracilis 102 littoralis 104 longicornis 102 norvegica 102 Schneideri 104 Cyclopinidtp 102 Cyclopoida 1 02 Diosaccidiv 54 Danielssenia 92 robusta 93 Fctinosoma 23 angulifrons 24 clavatum 26 compressttni 27 brevirostre 31 distinctum 29 gothiceps 30 Page. Herdmani 26 melaniceps 28, 29 ncglcctum 24, 32 obtiisnm 30 piopiiiqvum 25 proximiun 23 tetit'i'tnn 25 tenuipes I'.V F.ctitwsomidii' 23 Eurycletodt's 83 acnleatus 85 laticaudatus 84 latus 84 major 85 minutns 86 oblongns 84 serratus 83 F.nryte 10(5 longicauda 106 minor 106 I:nterpe 96 gracilis 97, 98 Enterpina 96 acutifrons 97 Fultonia 88 hirsuta 88 Gnathostoma 102 Goniopelte 99, 100 gracilis 100 Goniopsyllus 99, 100 rostratus 101 Halopliytopliilns 46 fiisifonnis 48 spinicornis 47 Harpacticida.' I' 1 Harpacticoida 19 Harpacticus 48 acutifrons 97, 99 gracilis 49 5<> 17 118 tenellus Harrietella simulans Hemimesochra claviilaris Hermannella diibia valida Idyanthe dilatata fdyella exigua major Idycea compacta gracilis graciloides Idywidce Ilyophilus pcrplexus Jonesiella l.aophonte abbreviate* brevifurca brevirostris littoralis macera simulans tenera Laophontidce Laophontodes expansus Leptocletodes debilis 88, Lichomolgt'liu pusilla Lichomolgidtr Lichomolgiis arenicola Longipediidce Mesochra . . exigua .... Mesocletades . Page. 49 73 73 68 69 110 110 111 .54 54 52 53 52 50 51 51 50 50 91 91 92 70 72 70 71 73 72 73 71 70 75 75 87 96 111 111 110 112 112 19 65 65 80 Page abyssicola 81 inermis 82 irrasus 81 monensis 80 Moraria 57 brevipes 57 Nannoptis 91 abyssi 91 palustris 91 Paracartia 15 Orani 16 spinicaudata 16 Parameira 59 intermedia 60 longiremis 59 Parastephos 5 pallidus 6 Phaennidiv 3 Platycopia 10 perplexa 11 pygmcea 13 Platycopiidw 10 Poecilostoma 110 Psammis 94 longisetosa 94 Pseudameira 61 furcata 62 gracilis 61 mixta 62 Pseudobradya 31 ambigua 40 attenuala 34 digitata 31 exit is 38 leptognntha 32 minor 38 parvula 36 pulcliella 37 pygnuva 39 scabrinscnla 33 tenella 35 Pseudocletodes 89 typicus 89 Page Pseudocyclopia .... 7 crassicornis 9 Giesbrechti 7 stephoides 8 Pseudocyclopiidce 7 Pseudocyclopidcp 14 Pseudocyclops 14 crassiremis 14 obtusatus 15 Pseudomolgus 112 arenicola 112 leptostyiis 112 Rhynchomyzon 107 falco 107 purpurotinctimi 108 Sapphirina 113 gemma Ill iris 114 salpae 114 Sapphirinidii- 113 Siphonostoma 107 Stenheliopsis 54 af finis 54 divaricata 55 Stenocopia 63 minor 63 Stephida' 4 Stephos 4 minor 4 Scotti 5 Sunaristes 19 pagnri 19 Tachidiida? 92 Xanttiocalanus 2 borealis 2, 4 fallax 3, 4 liirtipes 2 minor 3 propinqvus 3 Zosime 21 major 21 typica 22 valida . 22 LIST OF PLATES. The signature of the figures is in accordance with that given in the 3 preceding Volumes. The ciphers adjoining to the head-figures indicate the length in millimeters of the specimens drawn. PI. I. Xanthocalanus minor, Giesbrccht. PI. II. Stephos minor, Scott. PI. III. Parastephos pallidus, G. O. Sars. PI. IV. Pseudocyclopia Giesbrechti, Wolfcnden. PI. V. 1. Pseudocyclopia Giesbrechti (continued). 2. Pseudocyclopia crassicornis, Scott. PI. VI. Platycopia perplexa, G O. Sars PI. VII, 1. Platycopia perplexa, (continued). 2. Platycopia pygma^a, G. O. Sars. PI. VIII. Pseudocyclops crassiremis, Brady. PI. IX. Pseudocyclops crassiremis (continued). PI. X. Paracartia Grani, G. O. Sars. PI. XI. Paracartia Grani (continued). PI. XII. Sunaristes paguri, Hesse (male) PI. XIII. 1. Cerviniopsis clavicornis, G. O. Sars (male). 2. Zosime major, G. O. Sars. PI. XIV. Zosime valida, G. O. Sars. PI. XV. 1. Edinosoma proximum, G. O. Sars. 2. Ectinosoma angulifrons, G. O. Sars. PI. XVI. 1. Ectinosoma tenerum, G. O. Sars- 2. Ectinosoma clavatum, G. O. Sars. PI. XVII. 1. Ectinosoma compressum, G. O. Sars. 2. Ectinosoma tenuipes, Scott. PI. XVIII. 1. Ectinosoma distinctum, G. O. Sars. 2. Ectinosoma obtusum, G. O. Sars. PI. XIX. Pseudobradya digitata, G. O. Sars. PI. XX. Pseudobradya leptognatha, G. O. Sars. PI. XXI. Pseudobradya scabriuscula. G. O. Sars. 120 PI. xx i r Pseudobradya attciiuata, G. O. Sars. PI. XXIil. 1. Pseudobradya tenella, G. O. Sars. 2. Pseudobradya parvula, G. O. Sars. PI. XXIV. 1. Pseudobradya pulchella, G. O. Sars. 2. Pseudobradya exilis, G. O. Sars. 3. Pseudobradya pygrmea, G. O. Sars. PI. XXV. Pseudobradya ambigua, G. O. Sars. PI. XXVI. Bradya Scotti, G. O. Sars. PI. XXVII. 1. Bradya inacrochaeta, G. O. Sars. 2. Bradya ftircata, G. O. Sars. PI. XXVIII. 1. Bradya congenera, G. O. Sars. 2. Bradya simulans, G. O. Sars. PI. XXIX. Halophytophilus spinicornis, G. O. Sars. PI. XXX. Harpacticus tenellus, G. O. Sars: PI. XXXI. Idyjea graciloides, G. O. Sars. PI. XXXII. Idyaea compacta, G, O. Sars. PI. XXXIII. 1. Idyella major, G, O. Sars. 2. Idyella exigua, G. O. Sars 3. Idyantlic dilatata, G. O. Sars J PI. XXXIV. Stenlieliopsis affinis, G. O. Sars. PI. XXXV. Attheyella Schmeili, (Mrazec). PI. XXXVI. Ameira dubia, G. O. Sars. PI. XXXVII Ameira exilis, Scott J PI. XXXVIII 1. Paramcira longiremis, (Scott). 2. Parameira intermedia, (Scott). PI. XXXIX. Pseudameira gracilis, G. O. Sars. PI. XL. Pseudameira mixta, G. O. Sars. PI. XLI. Stenocopia minor, G. O. Sars. PI. XLII. Cletoinesochra major, G. O. Sars. PI. XLI1I. Cletomesochia nana, G. O. Sars. PI. XLIV. Cletomcsoclira rostrata, G. O. Sars. PI. XLV. Hcmimesochra clavularls, G. O. Sars. PI. XLVI. Laophonte brevifurca, G. O. Sars. PI. XLVII Laophonte tenera, G. O. Sars. PI. XLVIII Laophonte abbrcviata, G. O. Sars. PI. XLIX. Harriettella simulans. Scott. PI. L. Clctodcs Sarsi, Scott. PI. LI Cletodes pusillus, G. O. Sars. PI. LII. Cletodes leptostylis, G. O. Sars. PI. LII. Cletodes perplexus, Scott. PI. LIV. Mesocletodcs monensis, (Thompson). PI. LV. Mesocletodes abyssicola, (Scott). PI LVI. Mesocletodcs inermis, G. O. Sars. 121 PI. LVII. Eurycletodes serratus, O. O. Sars. PI. LVIII. Eurycletodes oblongns, G. O. Sars. PI. LIX. Eurycletodes nculeiitus, G. O. S;irs. PI. LX. Eurycletodes minutus, G. O. Sars. PI. LXI Leptocletodes debilis, G. O. Sars. PI. LXII. Pseudocletodes typicus, G. O. Sars. PI LXIII. Namiopus abyssi, G. O. Sars. PI. LXIV. Danielsscnia robusta, G. O. Sars. PI. LXV. Psammis longisetosa, G. O. Sars (male). PI. LXVI. Argestes tennis, G. O. Sars. PI. LXVII. Euterpina acutifrons, (Dana). PI. LXVIII. Clytemnestra scutellata, (Dana). PI. LXIX. 1. Cyclopina norvegica, Boeck. 2. Cyclopina brachystylis, G. O. Snrs. 3. Cyclopina littoralis, Brady. PI. LXX. 1. Cyclopina dilatata, G. O. Sars. 2. Euryte minor, Scott. PI. LXXI. Rhynchomyzon falco, Giesbrecht (male). PI. LXXII. Acontiophorus ornatus, (Brady). PI. LXX1II. 1. Hermannella dubia, G. O. Sars (male). 2. Lichomolgella pusilla, G. O. Sars. PI. LXXIV. Pseudornolgus arenicola, (Brady) PI. LXXV. Sapphirina iri, Dana $. PI. LXXVI. Sapphirina iris, Dana (male). Tachidiidae Copepoda Suppl. Volume PI. LXV G. O. Sars, del. Psammis longisetosa, G. 0. Sars (male) Tachidiidae Copepoda Suppl. Volume PI. LXVI G. 0. Sars, del. Argestes tenuis, 6. 0. Sars Tachidiidae Copepoda Suppl. Volume PI. LXVII G. O. Sars. del. Euterpina acutifrons, (Dana) Clytemnestridae Copepoda Suppl. Volume PI. LXVIII G. O. Sars. del. Clytemnestra scutellata, (Dana) Cyclopinidas Copepoda Suppl. Volume PI. LXIX G. O. Sars, del. 1. Cyclopina norvegica, Boeck. 2. brachystylis, G. O. Sars. 3. litoralis, Brady. Cyclopinidae Cyclopidae Copepoda Suppl. Volume PI. LXX j G. O. Sars, del. 1. Cyclopina dilatata, 6. 0. Sars. 2. Euryte minor, Scott. Ascomyzontidae Copepoda Suppl. Volume PI. LXXI G. O. Sars, del. Rhynchomyzon falco, Giesbr. t Acontiophoridse Copepoda Suppl. Volume PI. LXXII ,4-fr: ' , ' ' G. O. Sars, del. Acontiophorus ornatus, Brady Lichomolgidae Copepoda Suppl. Volume PI. LXXIII I . / \ Q. O. Sars, del. 1. Hermanella dubia, G. 0. Sars. 2. Lichomolgella pusilla, G. O. Sars. Lichomolgidae Copepoda Suppl. Volume PI. LXXIV ' / -^ A i7 v I'.i '} f { ^, I / ' 6. O. Sars. del. Pseudomolgus arenicola, (Brady). Sapphirinidae Copepoda Suppl. Volume PI. LXXV r: r I ** M - G. O. Sars, de . Sapphirina iris, Dana Sapphiriniclae Copepoda Suppl. Volume PI. LXXVI & y 3^ i "! i * y ' - . }} y i 6. O. Sars, del. Sapphirina iris, Dana .