Boone, Crustacea, Cruises of "Eagle" and "Ara," 1921-28 51 



of eleven tapering articles, and a smaller, inner branch consisting of 

 seven tapering articles. 



The external antennae have a short, wide, truncate peduncular 

 article which can be seen only in a basal view; the second article is 

 nearly twice as long as the first article, arises from the outer side of 

 the latter and extends as far forward as the distal margin of the first 

 visible segment of the antennulae, and is furnished with a series of 

 heavy, plumose setae along both lateral margins; the third article is 

 narrower and a little shorter than the second and curves outward dis- 

 tally like a horn; the inner lateral margin is furnished with very 

 long, plumose setae and the outer lateral margin is beaded and fur- 

 nished with fewer and shorter setae than the inner margin ; the fourth 

 article is approximately three-fifths as long as the third and is small, 

 cylindrical, supporting a well-developed flagellum composed of nine 

 or ten annulations, each of which is furnished on the distal margin 

 with several, long, stiff, radiating setae. 



The external maxillipeds are long, narrow and close-fitting; the 

 exognath has its merus very slender, somewhat curved and almost 

 three times as long as the ischium, extending a trifle beyond the distal 

 margin of the ischium of the endognath. The ischium of the endognath 

 is about one and one-half times as long as its merus, and is nearly 

 twice as wide as the exognath, becoming gradually wider distally with 

 the outer lateral margin convex, and the distal margin concave with 

 the inner distal angle more advanced than the outer; the merus is 

 slightly broader than the ischium and has its outer lateral and distal 

 margin rounded ; a slender, three- jointed palp arises subdistally from 

 the inner lateral margin and consists of a small, subcylindrical, basal 

 article, a longer, wider, more flattish second article, which has its 

 inner lateral margin unequally convex and set with a series of sub- 

 equal spines; the distal article is a little shorter than the preceding 

 one and tapers to a point distally ; its inner lateral margin is also set 

 with spines like those on the preceding article, but the distal spine is 

 hook-like and twice as long as any of the others. The tip of the merus 

 of the endognath reaches forward almost as far as the distal margin 

 of the second article of the external antennae. 



The first pair of legs are chelate and have the shape typical of 

 Raninidae and are subequal in both sexes and to each other. Each 

 has the coxa and basis short ; the ischium is thick, nearly half as long 

 as the merus, with the inner distal angle produced to a point, and with 

 a prominent, sharp, acuminate spine placed subdistally on the anterior 



