462 BULLETIN" 15 8, UNITED STATES NATIONAL MUSEUM 



equal in length, tipped with a stout claw and a swollen pad covered 

 with spines. Maxillipeds large and powerful, projecting far beyond 

 the lateral margins of the carapace; terminal claw considerably 

 shorter than the basal segment and strongly curved near its tip. 



The first four pairs of legs are biramose, the rami 2-segmented; 

 in the first pair the basipods are not swollen, the basal segment of 

 the exopod is broad and curved inward, and is usually folded against 

 the basal segment, with its tip overlapping the endopod. Its outer 

 margin is fringed with a row of fine saw teeth; the distal segment 

 is small and conical and tipped with three small spines. The endo- 

 pod is made up of a basal segment and two small conical processes, 

 each tipped with a minute spine; outside the base of the endopod 

 is a large plumose seta. The basipod segments of the second, third, 

 and fourth legs are swollen into large triangular sacs, which cover 

 the lateral sinuses between the thoracic segments, and thus become 

 visible in dorsal view. The legs themselves are attached to the ven- 

 tral surfaces of the sacs ; in all three pairs the basal segment of each 

 ramus is much wider than the terminal and is produced into a long 

 spine on one or both sides of the latter; the terminal segment is 

 conical with stout spines. The outer margin of each basal exopod 

 segment is armed with one or more rows of spiny teeth ; in the sec- 

 ond legs the concave distal margin of this segment also has a row of 

 teeth. In these three pairs of legs the outer spine of the basal exo- 

 pod segment reaches beyond the tip of the end segment. The fifth 

 legs are minute unarmed fingerlike processes attached to small knobs 

 on the ventral surface of the fifth segment near the posterior corners. 

 Total length, 10-12 mm. Carapace and free thorax, 8-9 mm. long; 

 carapace, 2 ; free thorax, 2.5 mm. wide. Ovisacs, 30 mm. long. 



Male. — Carapace one-half longer than wide, with a straight frontal 

 margin and a narrowed posterior end overlapping the second seg- 

 ment as in the female ; second, third, and fourth segments wider than 

 the carapace, but diminishing in width backward, the sinuses be- 

 tween the segments narrow, shallow, and angular. Fifth segment 

 little more than half the width and a third of the length of the fourth 

 segment, with rudiments of fifth legs on its ventral surface. Genital 

 segment wider than the fifth segment and two and a half times as 

 long, with strongly convex sides. Abdomen 3-segmented, segments 

 diminishing in width posteriorly, the anal segment the longest, the 

 second segment the shortest. Caudal rami short, each tipped with 

 three short spines. 



Antennae and mouth parts like those of the female; maxillipeds 

 relatively larger and tipped with very powerful claws. First and 

 second legs similar to those of the female, except that they are more 

 plentifully armed with short spines. In the third and fourth legs 

 the terminal segments of the rami are lengthened, especially the 



