COPEPODS OP THE WOODS HOLE KEGION 181 



surface of the segment. Each claw is swollen basally and narrowed 

 distally ; the basal portion is armed with a slender spine on the dorsal 

 surface nearer the outer margin ; the slender terminal portion is split 

 for its entire length into two strongly curved rami, whose tips reach 

 beyond the ends of the caudal rami. The specific name flssilis (split) 

 alludes to this division of the terminal portion of the claws. Both 

 of the end setae of each caudal ramus are jointed near the base, and 

 the inner one is more than half as long as the entire body. The basal 

 segments of the first antennae are stout and the second segment is 

 more like that of the male in spinicauda, densely setose along its 

 anterior margin. In the second antemiae the exopod is very slender 

 and is tipped with two small subequal setae; the endopod is also 

 quite slender, its end segment has two smooth spines on its imier 

 margin, and five at the tip, no one of which is either enlarged or 

 jointed. The swimming legs are similar to those of the preceding 

 species, but the exopods do not have the fringe of spines along their 

 outer margins; the fifth legs are a little smaller but no different in 

 pattern, except that the middle apical seta of the distal segment is 

 proportionally longer. 



Total length, 0.35-0.45 nmi. 



Male. — Unknown. 



Remarhs. — This species is a little larger than spinicauda and can 

 be distinguished at once by the split claws on the dorsal surface of 

 the anal segment. It is not so common as the preceding species and 

 was found only in the single locality recorded above. The dorsal 

 claws are relatively much larger and must render efficient service as 

 prehensile organs. 



Family HARPACTICIDAE 



Genus HARPACTICUS Milne Edwards, 1838 



Body either compressed or somewhat depressed, and tapered 

 posteriorly; head fused with first segment; rostrum curved down- 

 ward and bluntly rounded; urosome 4-segmented in female, 5-seg- 

 mented in male; caudal rami short and divergent, one of the terminal 

 setae considerably elongated ; a single ovisac. First antennae 8- or 9- 

 segmented, geniculate in the male, the last segment of the proximal 

 portion swollen and forming the hand of a chela, whose dactylus is 

 the terminal portion of the antenna; exopod of second antennae 

 2-segmented ; first legs with a 2-segmented exopod and a 3-segmented 

 endopod ; rami of second, third, and fourth legs 3-segmented, second 

 endopod modified in male ; fifth legs 2-segmented, well developed in 

 female, the basal segment rudimentary in male. 



