COPEPODS OF THE WOODS HOLE REGION 289 



Remarks. — The short and wide caudal rami and the curious claws 

 on the basipods of the second legs will identify the species. Its 

 home appears to be within the sand at moderate depths, for which 

 the extremely narrow and vermiform shape of its body seems well 

 suited. 



Genus PARASTENOCARIS Kessler, 1913 



Body small, cylindrical and elongate, about the same diameter 

 throughout; cephalic segment nearly as long as the first three free 

 segments combined; urosome nearly as long as metasome; genital 

 segment not divided ; anal segment nearly twice as long as penulti- 

 mate segment; caudal rami long and narrow, apical setae as long 

 as urosome. First antennae 7-segmented, strongly geniculate in 

 the male; exopod of second antennae 1-segmented, attached to the 

 side of the basal endopod segment and tipped with a single seta; 

 maxilliped well developed, with a stout terminal claw. Exopods of 

 first, second, and fourth legs 3-segmented, of the third legs 2-seg- 

 mented; endopod of first leg 2-segmented, of the three following 

 pairs 1-segmented; third legs completely transformed in the male 

 into a copulatory organ; endopod of fourth leg also modified; 

 segments of fifth leg fused into a single lamella. One species known. 



PARASTENOCARIS BREVIPES Kessler 

 FlGUBE 178 



Parastenocaris hrevipes Kesslee, Zool. Anz., vol. 42, p. 310, 6 figs., 1913. 



Occurrence. — ^Washed from the sand close to the shore of Nobska 

 Fresh Pond and Waquoit Fresh Pond, Falmouth, August, 1927; 

 abundant in both ponds. 



Distribution. — Austria, fresh water (Kessler). 



Color. — Body transparent and colorless, without pigment; eggs 

 tinged with blue, increasing in color with development ; eye invisible. 



Female. — Epimeral parts of cephalic segment turned downward 

 and inclosing the bases of the antennae and mouth parts; second 

 (first free) segment longer than any of the following metasome seg- 

 ments. Urosome a little shorter than the metasome; genital seg- 

 ment not divided ; anal segment almost as long as the two preceding 

 segments combined ; caudal rami four times as long as wide, swollen 

 through the center, where each carries a transverse row of setae, ter- 

 minal setae curved like parenthesis marks. Second segment of first 

 antenna the longest, with three large setae along its dorsal midline 

 nearer the distal end, and a fringe of short hairs on its anterior mar- 

 gin. First endopod as long as exopod, tipped with two elongate 

 unequal setae; second and third endopods shorter than the basal 

 exopod segment, the second one tipped with two very short spines 



