﻿coria'ODA 



147 



Ri of the inaxillulae and the presence of a Se Re I pes I. The two (reuera arc very nearly related, 

 but as the five species of Uiidcuclnrtc form a very natural oroup I prefer to refer this species to 

 Chinidiiia. 



V/ 



42. Chirudina abyssalis u. sp. 



(PI. V figs 5 a— f; text-figs 40 a— c). 



Description. i% Size of specimen from Thor St. 183 was 5-4 mm.; anterior divi.sion 43 mm.; 

 urosome 11 mm. 



The head is gradually rounded in front, without any crest; the rostrum is rather short, but 

 strong, directed downwards and slightly backwards (text-fig. 40 a). The cephalothorax, which is moder- 

 ately slender and slightly attenuated towards the front part as well as towards the end, is about 2-5 

 as long as wide; the first thoracic tergite is, at least dorsally, well separated from the head; the fifth 

 somite, which is well separated in front, 

 is laterally' not produced, and has evenly 

 rounded corners (fig. 5 a). The anterior 

 division is about four times as long as the 

 abdomen. 



The genital somite, which is a 

 little wider than deep and as deep as long, 

 is in dorsal outline almost synnnetrical; 

 the ventral surface is anteriorly rather 

 suddenly produced and posteriorly gradu- 

 ally sloping; the genital area is in ventral 

 view seen to be somewhat different from 

 that of the preceding si^ecies. The genital 

 somite possesses, dorsally, along hinder margin, short hairs, and ventrally tufts of longer hairs; the fol- 

 lowing somites are more and less hairy, the hairs being longest dorsallx' and \-entrall\'. The caudal 

 rami are about as long as wide; the terminal setae are distinctly shorter than the abdomen and about 

 three times as long as the Si. 



The antciniitlar extend to the end of the caudal rami; the measurements are very like those 

 of the preceding species. The exopodite of the oiiteiniac is i-6 as long as the endopodite; the second 

 segment of the endopodite has 8 setae in L,i and 7 in L,e; the first segment of the exopodite, which 

 is one third as long as the second, has inside a short protuberance with a short hair; the second seg- 

 ment has only a terminal seta. The iiiaiidibnlac have, as shown in fig. 5 b, a rather characteristic shape, 

 and the viaxillulac are completely like those of CIi. /oisfnli/frti. The luaxiilac (fig. 5 c) are only 

 slightly produced basally, and have the .spinous areas on the hinder surface of the four proximal lobes 

 distinctly different from those of most species of /s>i'r/'//v7/r/ (cf. fig. 9d); in the first lobe a smooth area 

 is found surroinided by spines. The inaxillipvds are scarcely different from those of the preceding species; 

 beyond the vSi 3 in the third basi|n)dite a longitudinal row of longer and shorter teeth is found (^text- 

 fig. 40c); similar teeth were found in Cii. pnstiilifmi, I)ut not in Cli. Strcctsii. 



19* 



Text-fig. 40. Chii-udiiui ahyssalis II. sp. 

 a. f 9. Head X iS. b. Pes I >; 33. c. MaNillipes .sin. Basp. Ill iu post 



view X 87. 



