﻿COPEPODA 



somite. The L,i 2 of the niaxilhilae has 2 not 3 setae. The Ri 2 of the fourth foot has no "corona of 

 spines", but a number of fairh' long bristles, and the fifth feet seem to be somewhat different. 



73. Onchocalanus cristatus Wolf. 

 (PI. VII figs 6 a— e; PI. VIII figs 17 a— f). 



1904. Xanthocalanus cristatus ii. sp. Wolfenden, p. 119. pi. 190S. Onchocalanus cristatus Wolf. Farran, p. 49. 



IX figs 18 — 19. 190.S. Xanthocalanus cristatus Wolf Wolfenden, p. ;^4. 



1905. Onchocalanus trigoniceps n. sp. G. O. Sars, p. 20. 190S. — — — v. Bremen, p. 62 fig. 70 



1906. Xanthocalanus cristatus Wolf. Pearson, p. 20 1909? Onchocalanus cristatus Wolf. A. Scott, pp. 82 — S3, pi. 

 igo6? — siniilis n. sp. Esterly, pp.68 — 6g,pls9-i3. XXXIV figs i — S. 



1907. Onchocalanus cristatus Wolf. G. O. Sars, p. 3. 191 1. — — — Wolfenden, pp. 277— 27S. 



Description. f$. Size of female from Tlior St. 183 was 8-15 mm.; anterior division 6-45 mm.; 

 urosome 170. Another specimen measured 7-5 nun. Wol fen den's specimen measured 5-5 mm., Sars's 

 7 nnn. and vScott's 6-6 mm. 



The shape of the bod)- is like that of O. wngiiiis, Imt it is more slender; the first as well as 

 the fifth thoracic somite is well marked out in front. The head (PI. \"III fig. 17 a) is well raised, and 

 surmounted with a dorsal low crest, visible in dorsal as well as in lateral view. The rostrum consists 

 of a basal portion and two fairly long somewhat divergent spines witliout distinct terminal filament. 

 The lateral corners are triangularly produced and terminated with a distinct tooth. 



The ahdovicti is a little more than one fomth as long as the anterior division; the genital 

 somite is like that of O. i/iagiiiis, but is less produced below. The comparative length of the abdominal 

 somites and the fnrcal branches is 28, 18, 13 and 6; the somites are hairy in a similar way as in 

 the other species. 



The anteiiiiiilaf are like those of O. jiiagniis, and extend about to the end of the furca; the 

 only difference is found in the slighth- different measurements of the segment 13, which is 124 (not 

 1-4) as long as segment 12, and of segment 24 which is i-i as long as segment 23 (not a little shorter). 

 The antennae, viandibnlac and inaxillulae are scarceh' different from those of O. magnus. Tlie viaxillar 

 are like tho.se of the preceding species; the endopodite possesses in addition to a short seta of usual 

 structure a long slender .sensory seta and 5 fairly long one.s, the .slightly enlarged part of whicli is 

 more or less "brush-shaped". The inaxillipeds are like tho.se of the preceding species, but the third 

 outer segment has 4 instead of 3 strong curved .spines. The A>-*/ pair of legs differs only by rather 

 unimportant details in the armature of the posterior surface. The Se of the first inner segment is 

 long, slender, and distinctly pointed in the second pair of legs. The third as well as the fourth pair 

 of legs differs from O. magmts in the details of the arrangement of the hairs, and by the curiously 

 contorted terminal spine. The z^///? pair of legs consists of three segments, of which the third, attenuated 

 one, is longer than the second, but shorter than the two basal ones combined; it has, as seen in fig. 

 6 a PI. VII, a terminal and two outer spines. The anterior surface is smooth, while the sides as well 

 as the posterior surface are all over covered with fairly strong setae or spines. 



The labni/n (PL VIII fig. 17 a) etc. are not in an}- features of great interest different from the 

 corresponding organs of the preceding species. 



