512 PROCEEDINGS OF THE NATIONAL MUSEUM vol.99 



with one seta at posterior angle of third lateral elevation. Coxal 

 plates of somites five and six not so long as their corresponding somites 

 and visible in dorsal view. Sixth somite possessing two pairs of setae 

 on dorsal surface. Seventh somite similar to sixth but coxal plate 

 not visible in dorsal view and somite with one transverse row of three 

 setae located on each side of midline. An elevated genital papilla 

 present on midventral line of last somite of male specimens. 



Pleon. — Composed of three somites, two short anterior somites and 

 a triangulate pleotelson. Lateral border of first and second somites 

 extending somewhat posteriorly and having truncate apex beset with 

 tiiberculations and a seta. An elevated, laterally directed papilla bear- 

 ing a seta at its apex is located medial to each lateral extension. Pos- 

 terior margin of somites having setae along dorsal portion. Pleotelson 

 with acutely pointed apex, above which is a narrow, cone-shaped, setif- 

 erous papilla. Lateral and anterior to that papilla are two widely 

 conical setiferous papillae. No pleopods present. Uropocls two- 

 branched, first segment or peduncle extending in length almost to end 

 of pleotelson. Inner uropod branch as long as peduncle and composed 

 of four subequal segments, outer branch two-jointed and one-half the 

 length of inner branch, 



Fwst antennae. — First segment thick, three times the length of 

 second, and with a series of large spinelike tubercles on medial margin. 

 Third segment slightly shorter and much narrower than second. 

 Fourth segment about one-half the length of third segment and bear- 

 ing two branches, the outer of which is composed of three subequal 

 segments, inner branch about as long as fourth segment and composed 

 of two joints. Number of segments of antennal branches is reduced 

 by one in very small specimens. A corresponding reduction occurs in 

 the number of joints to the branches of the uropods. 



Second antenna. — Small, located below first antenna and concealed 

 from dorsal view. It is composed of a three-jointed, flattened peduncle 

 whose segments decrease in size distally. First two segments with 

 tuberculate borders. Flagellum composed of two segments the first of 

 which is four times the length of the last. A "sensory" ciliated bristle 

 is located at inner angle of tip of first flagellar segment. Setae at tip of 

 last flagellar segment pointed, not filamentous. 



Maxilliped. — ^With two coupling hooks; palp composed of four 

 articles, the first two of which are wider than endognath. Toothed 

 setae present on medial margin of last three palp segments. 



First pair of maxillae. — Composed of two lobes and a biflagellated 

 appendage. Inner lobe with 4 apical setae, outer lobe with 10 apical 

 setae. Biflagellate appendage, which is located external to outer lobe, 

 appears to be two-jointed, last joint bearing two elongate flagellalike 

 spinulate setae, both of which exceed combined length of prior seg- 

 ments. 



