COPEPODA 201 



inent 19. The mouth-appendages are comparatively slightly transformed; the third basipodite of the 

 mandibulae has, in addition to a fairly long Se i and a quite rudimentary Si 2, a small rounded process. 

 The maxillulae and the maxillae are scarcely less developed than in the female; the maxillipeds are 

 comparatively less slender, but the amalliform seta of the second basipodite is well developed as in 

 the female. The natatory legs are practically like those of the female, but the spinulation, especially, 

 of the anterior surface is less developed, and the medial terminal tooth of the anterior surface of the 

 fourth pair of legs is better developed; the terminal seta of Re III pes II has about 60 serrations. Along 

 the outer margin of the second basipodite of the third pair of legs, a lamina with a row of short spines 

 is found. 



The fifth pair of legs, which in natural position is seen to extend a little beyond the end of 

 the abdomen is very much like that of S. obtusifrons. The right endopodite (PL VIII fig. 9 b) is rather 

 short, distally somewhat triangularly produced, and rather suddenly attenuated to a fairly long spine. 

 The right basipodite (fig. 9 a) is, outwards, produced into a long process which is fused with the first 

 outer segment; a terminal process of somewhat triangular shape, as in S. magnus, as well as a median 

 one is observed; the second outer segment is rather short and somewhat curved, and the third one is 

 short, flat, slightly curved and somewhat attenuated (fig. 9 a). The basipodites of the left foot are long 

 and slender; the comparatively short and slender endopodite is slightly curved, and indistinctly divided 

 into two proximal segments of about equal length as well as a short third segment with a fairly 

 slender terminal seta beyond a rounded process. The left exopodite is comparatively long and clumsy ; 

 its first segment is the longer, and has two triangular processes, while the third one is the shortest, 

 and hairy (PI. VII fig. n b). 



YQ (St. V). Size of female from Thor St. 183 was 3-49 mm.; anterior division 271; urosome 

 078 mm. 



The shape of the body shows the usual difference from that of the adult female; the distal 

 segments of the antennulae are comparatively longer; the segment 19 is n as long as segments 80^9; 

 the fifth pair of legs is somewhat smaller, but in other respects scarcely different. 



Occurrence. The S/S Thor has taken this species at three stations iu deep water viz: 



V 9 1904 St. 285 6249 L. N. i846 L. W. Yt. 500? M. Wire i f?. 

 >/ 7 1904 St. 180 6i34 L. N. i9 o5 L. W. Yt. 1800 M. Wire 2 f ? + i f d 1 . 

 / 7 1904 St. 183 6i3o L. N. i7o8 L. W. Yt. 1800 M. Wire 2 f?, 3 f<?, 2 y? (V). 



Distribution. The species has only been recorded twice by Farran off the west coast of Ire- 

 land at looo and at 700 fathoms. 



Remarks. This species is certainly identical with Farran's species, as they do not differ in any 

 features of interest. Though, as far as the description goes, it agrees completely with Sars' Scolecithri- 

 cella gracilis, especially in the structure of the fourth pair of legs, I prefer to refer it to Farran's 

 species, as it is well distinguished from Scolecitricella according to Sars' own definition. 



The described male, which is well distinguished from that of S. obtusifrons by its long and more 

 slender fifth foot, I have, on full consideration, referred to this species rather than to S. valid-its with 



The Ingolf-Expedition. III. 4. 26 



