54 



BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



obsolete; first antennae considerably dilated basally and densely 

 fringed with large curved aesthetasks; two proximal segments of 

 first exopods distinctly separated; fifth legs -large, biramose and 

 asymmetrical; endopods 1-segmented, right club-shaped, left longer 

 and much narrower; right exopod 2-segmented, left 3-segmented, 

 end segment spiniform. Total length, 2-2.25 mm. 



Remarks. — ^With designated this species as a North Atlantic and 

 arctic form, frequenting the intermedial layers. All the present 

 specimens came from the trawl wings, which suggests that as the 

 species comes farther south and nearer the shore it seeks the colder 

 water near the bottom. 



GAroiUS BREVISPINUS (G. O. Sars) 

 FiGUEB 34 



Chiridius hrevispinus Saes, Norwegian North Polar Expedition, 1893-1896, 



vol. 1, no. 5, Crustacea, p. 68, pi. 19, figs. 1-11, 1900. 

 Gaidius brevlspinvs Sars, Crustacea of Norway, vol. 4, p. 162, suppl. pi. 6, 1903. 



Ooownrence. — One male 

 from trawl wings, Station 

 2219, Albatross; 1 female 

 from trawl wings, Station 

 2236, Albatross, off 

 Marthas Vineyard. 



Distribution. ■ — Polar 

 Basin (Sars); Faroe 

 Channel (Norman) ; Den- 

 mark Strait, Iceland 

 (With) ; Arctic Ocean 

 (Mrazek) ; North Atlantic 

 (Farran) ; North Sea (van 

 Breemen) ; English seas 

 (Pearson) ; Gulf of Maine 

 (Bigelow), 



Color. — No statement 

 regarding color has yet 

 appeared. 



Female. — Spines at posterior corners of fifth segment pointed 

 diagonally downward ; urosome one-third as long as metasome ; geni- 

 tal segment flattened ventrally ; caudal rami divergent ; two proximal 

 segments of first exopod separated, but the basal segment has no 

 outer spine. Total length, 3.9-4.8 mm. 



Male. — Considerably smaller than female; spines at posterior 

 corners of fifth segment smaller and shorter ; two proximal segments 

 of first exopod separated, neither of them with outer spine; fifth 

 legs biramose, asymmetrical; endopods 1-segmented, club-shaped. 



Figure 34. — Oaidius hrevispinus : a. Female, dorsal 

 1), fifth legs of male {r, right leg) 



