COPEPODA 



239 



From X. hirtipes and borealis, to which it is very nearly related, it seems to differ by greater 

 size, by comparatively shorter antennulae, which do not reach to the end of the genital somite, and 

 by 10 instead of 9 setae in the exopodite of the antennae. 



78. Xanthocalanus claviger Th. Scott. 

 (Text-figs 78 a— d). 



1909. Amallophora claviger n. sp. Th. Scott, pp. 124 — 125, pi. Ill figs 1 — 11, pi. IV figs 13 — 17. 



Description, f <$. Size of male from Thor St. 183 was 4-55 mm.; anterior division 3-22; uro- 

 some 133 mm. 



The shape of the body is like that of X. borealis\ the head has no crest; the rostrum is 

 broken but seems to be fairly long, and is directed somewhat backwards. The lateral corners of 



Text-fig. 78. Xanthocalanus claviger Th. Scott, f c?- 



a. Abdomen X 23. b. Pes V sin. Re II — III in situ from the left side X 122. c. Pes V sin. Re II — III in 



ant. view X 240. d. Pes V dext. in exterior view X 122. 



the thorax are regularly rounded. The head and the fourth somites are almost completely fused 

 with the following ones. The anterior division is 24 as long as the urosome; the comparative length 

 of the abdominal somites are seen in the fig. 78 a. The serrated seam along the hinder margins is 

 poorly developed. 



The antennulae extend distinctly beyond the end of the thorax to the end of the second ab- 

 dominal somite. Segments 8029 are only in front indistinctly separated from segments 10 — 12, which 

 are completely fused; these segments are fairly well separated from segment 13, which is well 

 separated from segment 14; the following segments are well separated from each other. A complete 

 "trithek" is found in segments 3 — 9; "iBsthetasken" are found in segments 10 — 19, but are wanting in 

 segments 20 — 24. Small proximal setae are seen in segments 12, 14, 16 and 18. 



The exopodite of the antennae is 1-5 as long as the endopodite, which has 6 setae in the 

 outer and 8 in the inner lobe of the second segment. The manducatory part of the mandibulae is 

 soft-skinned and very long and slender, with delicate but distinct teeth; the third basipodite is widened 



