288 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



rostrum triangular and rather sharply pointed at its tip. Urosome 

 nearly as long as the metasome; abdominal segments increasing in 

 length posteriorly; caudal rami as wide as long and divergent, their 

 inner margins semicircular, their outer margins nearly straight, each 

 tipped with three setae, the middle one much longer than the other 

 two, and an appendicular seta on the ventral surface. 



First antennae 7-segmented, slender and twice geniculate at the 

 third and fifth segments; fourth segment with a stout aesthetask, 

 which is bent backward at its center. The last two segments of the 

 antenna are turned forward, and since the aesthetask is nearly as 

 wide as these segments, the antenna appears bifurcate at the fourth 

 segment. Distal segment of second antenna with five apical setae, 

 all the same length; exopod very slender, 1-segmented, attached to 

 the side of the basal endopod segment and tipped with two minute 

 setae. Second segment of maxilliped scarcely swollen at all, with 

 smooth margins; terminal claw as long as the second segment, with 

 a small bristle on its inner margin near the base. 



Endopod of first legs just reaching the tip of the second exopod 

 segment, its end segment a little longer than the basal segment and 

 tipped with two unequal setae, the inner one twice the length of the 

 outer. The second leg carries on the anterior surface of its second 

 basipod a stout hooked claw or chela; the endopod does not quite 

 reach the tip of the first exopod segment, is very slender, and the 

 basal segment is twice the length of the distal segment, the latter 

 having two unequal apical setae. The middle segment of the second 

 exopod is much shorter than the other two segments and almost 

 spherical; the end segment is turned inward at its center, and its 

 single apical spine extends across the body at right angles. The 

 fourth endopod only reaches the center of the basal exopod seg- 

 ment ; its proximal segment is twice the length of the distal segment ; 

 the latter has a single apical seta, much longer than the whole ramus 

 and plumose only at its tip. The two basal segments of the fourth 

 exopod are elongated; the end segment is much shorter and carries 

 three apical setae. 



The fifth legs are very divergent, and each is made up of a single 

 fused lamella, tipped with an exceptionally long seta; on the inner 

 margin near the tip are five very short setae, the second one from 

 the tip filiform; below these setae at about the center of the inner 

 margin is a huge acuminate spine. Behind the fifth legs on the an- 

 terior portion of the genital segment is another pair of divergent 

 lamellae, representing the sixth legs; each is armed on its outer 

 margin with a short spine and at its apex with three slender setae, 

 the inner one much shorter than the other two. Total length, 

 0.62 mm. 



