﻿COPEPODA 



83 



(fig. 5 a) the terminal spine has about 80 densely placed, partly- fused, spinules; in other respects, excejjt 

 the arrangement of pores, which, except for the more medial ])osition is like that of Cli. obtusi/rons 

 etc., the legs are like those of preceding species. 



Occurrence. The S/vS. Thor has gathered a few specimens of this species at the following 



two stations. 



^Va 1904. St. 154. 65-27 L. N. 27°io L. W. Yt. ? Wire 3 f?. 

 'V7 1904. vSt. 1S3. 6i°30 L. N. i7°o8 L. W. Yt. 1800 M. Wire 2 f?. 



Remarks. This species, which seems to stand between the species of Cliiridius without rostrum 

 and Ch. itasutus, is well characterized by the shape of the rostrum and the position of the glau- 

 dular pores. 



19, Chiridius obtusifrons G. O. Sars. 

 (Plate II figs. 2 a — b; text-figs 20 a — e). 



1897. Pseudocalanus ariD.atus Boeck. Vauhiiffcii, p. 279, tig. 6. 



1900. Chiridius arinatus Boeck. G. O. Sars, pp. 29— 30, pi. XVII. 



1902. - — Mrazek, pp. 521 -—22. 



1903. Chiridius obtusifrons 11. sp. G. O. Sars, pp. 29— 30, pi. 17. 



1904? 

 1907. 



— — G. O. Sars. Wolfenden, p. 131. 



— Vauhoffeni n. sp. Wolfendeu, p. 117, pi. IV 



fi,«,- 23. 



— obtusifrons G. C). Sars. Koefoed & Damas, 



p. 408. 



1907. Chiridius arniatus Boeck. Vaulic'lffcii, p]). 519 521. 



1908. — obtusifrons G. O. Sars. v. Bremen, pp. 34 



—35, fig. :•,-!■ 



1909. nee. Chiridius? obtusifrons G. (). S;irs. \. Scott, ]). 43, 



pi. XLIV figs I 3. 

 1913. pars. — arniatus Boeck. Stephensen, pp. 316 317. 



Description. i% vSize: vSpecimeu from Thor vSt. 214 measured 439 mm.; anterior division 3-12 

 mm., urcsoine 1-27 mm. Sars' specimens measured 4-2 mm. and Vauhoffens 45 mm. 



b 



The shape of the body is as figured by Sars 

 (of. text-fig. 20 a). The articular membrane between 

 the head and first thoracic tergite and between the 

 fourth and fifth thoracic tergite (except in the middle) 

 is often wanting; in the articular membrane be- 

 tween the last thoracic and the first abdominal 

 somite chitinous lists of a rather curious structure 

 are found (text-fig. 20 c). According to most authors 

 no rostrum is observed; in several specimens, ho- 

 wever, the rostrum was represented by a very short 

 spine, sometimes showing trace of bifurcation as a 

 median line, when observed from beneath. The 

 anterior division is 2'4 as long as wide, and 2\ as 

 long as the abdomen. The genital somite, which 

 has a receptaculum semiuis of a similar structure 

 as in CIt. aniiafits^ but more slender, is I'Z as long 

 as the fourth somite; the f ureal rami are almost 

 twice as long as wide (text-fig. 20 d). 



The aiiti-ni/iilac, which almost extend to the 



Text-fig. 20. C/itriditis chtusifroiis G. O. Sars. 

 a. Cephalosonic X 9. ''• Genital somite in lateral view X 3'- 

 c. Genital somite in dorsal view X 33- <'• •^"•■»' somite etc. 

 in dorsal view X 6o. e. (Downwards to the left) pes II in 

 anterior view X 60. f. (In the middle above) pes III in an- 

 terior view X 60. 



n* 



