250 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



minute spines. The maxillipeds are strongly developed with a 

 slender apical claw longer than the second segment and curved near 

 its tip where it is armed with seven or eight minute cilia placed 

 some distance apart. Outside of the claw and attached to its base 

 is a long slender accessory spine. 



The rami of the first legs are about equal, the three segments of 

 the exopod the same length and swollen through the center, the two 

 basal segments each with a single spine on its outer margin, the end 

 segment with two spines and two setae, the outer seta geniculate. 

 The two segments of the endopod are also equal in length, the basal 

 segment with a seta on the inner margin near the center, the distal 

 segment with two unequal apical setae. Rami of the second legs 

 subequal, the three exopod segments elongate and narrow, the two 

 basal segments with one long and three short spines on the outer 

 margin, the end segment with three unequal apical setae and no 

 spines. The two endopod segments are sparsely fringed with 

 minute hairs on the outer margin, the basal segment has a slender 

 seta on its inner margin, and the distal segment has a single lorn; 

 apical seta. In the third and fourth legs the exopod is considerably 

 longer than the endopod and its segments are unequal. The two 

 basal segments are unarmed on their inner margins, the distal seg- 

 ment of the third exopod has a long inner seta, two apical setae, 

 and two outer spines. The distal segment of the fourth exopod has 

 two short outer spines, one long spine at the distal corner, two 

 unequal apical setae, and two modified inner setae. Each of the 

 latter has an elliptical swelling near its tip, with a dark central 

 spot, and ends in a mucronate point. The endopods of the third and 

 fourth legs are tipped with two unequal setae. The basal expan- 

 sion of the fifth legs is nearly as long as the distal segment, with 

 two unequal apical setae and its inner margin minutely denticulate. 

 The distal segment is oval, with a single elongate apical spine and 

 four shorter setae on the outer margin. Total length, 0.35-0.45 mm. 



Male. — Body similar to that of the female except that the cephalic 

 segment is relatively longer, the genital segment is shorter, and the 

 urosome is 5-segmented. First antennae twice geniculate, once be- 

 tween the second and third segments, and again between the fourth 

 and fifth segments, the last three segments usually turned backward. 

 The second antennae, mouth parts, and swimming legs are like those 

 of the female, without sexual modifications. The first endopod is 

 tipped with two unequal setae, the three following endopods each 

 with a single long seta. The fifth legs are reduced in size ; the basal 

 expansion is as long as the distal segment, is tipped with two short 

 setae, and has a smooth inner margin. The distal segment is very 

 small, with a long apical spine and three much smaller ones on its 



