COPEPODS OF THE WOODS HOLE EEGION 231 



sented by a pair of plates on the ventral surface of the genital seg- 

 ment, each armed with three setae. Total length, 0.35-0.45 mm. 



Remarks. — This species may be distinguished by the shape of the 

 rostrum and the structure of the first and fifth legs. It is evidently 

 a bottom species living in or on the sand, and it has never before 

 been reported from this side of the Atlantic. 



Family CANTHOCAMPTIDAE 



Genus CANTHOCAMPTUS Westwood, 1836 



Body slender and cylindrical, metasome only a little wider than 

 the urosome; head fused with the first segment; rostrum rudi- 

 mentary; urosome 4-segmented in female, 5-segmented in male, the 

 segments fringed with spinules along their posterior margins; 

 caudal rami somewhat longer than wide. First antennae 8-seg- 

 mented: exopod of second antenna 2-segmented; rami of first four 

 pairs of legs 3-segmented, except the fourth endopod, which is 

 2-segmented ; all the endopods or those of the first two pairs of legs 

 transformed in the male; fifth legs 2-segmented, distal segments 

 rather small. 



KEY TO THE SPECIES (FEMAIJIS) 



1. Anal operculum armed with 5 or 6 simple serrate spines ; basal 

 expansion of fiftli legs not reaching: center of distal seg- 

 ment staphylinoides (p. 231) 



Anal operculum armed with 10 or 12 spinules bifid at the tip; 



basal expansion reaching tip of distal segment minutus (p. 232) 



CANTHOCAMPTUS STAPHYLINOIDES Pearse 



Figure 155 



Canthocainptus staphylinoides Pbiarse, Studies Zool. Lab. Univ. Nebraska, no. 

 65, p. 151, pi. 15, figs. 14-21, 1905. 



Occurrence. — Fifteen specimens, including both sexes, were ob- 

 tained from wet moss along the shores of Jenkins Pond, Falmouth, 

 July, 1927. 



Distribution. — Eastern Nebraska and Nantucket Island (Pearse). 



Color. — Body yellowish green, inclined to reddish in the male; 

 eggs and ovisac pale green ; eye bright red. 



Female. — Moderately slender; cephalic segment shorter than the 

 rest of the metasome; urosome nearly as wide as metasome, its seg- 

 ments fringed with long spinules on their posterior margins on the 

 ventral and lateral surfaces ; genital segment only partially divided ; 

 anal operculum armed on its posterior margin with five or six stout 

 serrate spines, which are as wide as long. Aesthetask on fourth 

 segment of first antenna not reaching the end segment; exopod of 



