Boone, Crustacea, Cruise of "Alva," 1931 99 



fifths of the carapace ; the proximal third of the branch is thick, 

 composed of numerous small rings, the distal two-thirds is fine 

 and thin ; the inferior branch is very fine and only two-thirds as 

 long as the superior branch. 



The antennae have the first peduncular article strong, with the 

 dorsal margin unevenly rounded; the inferior distal outer angle 

 produced to a strong lateral point ; the second and third articles 

 are reduced, especially the second article, both lying beneath the 

 scaphocerite and together extending less than one-fourth of its 

 length; the flagellum is one and one-half times as long as the 

 entire body. The scaphocerite is widest across the proximal fourth, 

 the inner lateral margin being convex here and tapering distally ; 

 both distal lateral margins converge nearly obliquely from a point 

 opposite the subdistal lateral spine, toward the apex, which is blunt- 

 ly rounded ; the inner lateral border has a fine web of short setae, 

 which become shorter toward and on the distal margin. The scapho- 

 cerite extends the distal third of its length beyond the rostrum and 

 is elongate, with the outer lateral border thickened and terminating 

 in a small, subdistal tooth. The inner lamina is thinner and on the 

 inner distal portion is marked by a series of oblique grooves alter- 

 nating with ridges that radiate toward the outer margin. 



The external maxillipeds of an adult male extend more than 

 two-thirds of the length of the scaphocerite and have the dactyl 

 modified, it being about three-fifths as long as the outer, longer 

 margin of the propodus ; the dactyl arises from the inner distal 

 angle of the propodus, is cylindrical, but tapered to a narrowed 

 point both proximally and distally and beset with a few setae 

 on the proximal inner lateral margin; the outer distal angle of 

 this propodus is a blunt node that projects beside the narrowed 

 base of the dactyl nearly a fifth of its length and is tipped distally 

 with a dense tuft of setae which is nearly half as long as the 

 dactyl. The female dactyl is three-fourths as long as the propodus, 

 tapered distally only, and is setose on both margins. 



In both sexes the first and second pairs of chelipeds have the 

 merus produced at the ventral inner distal angle into an an- 

 trorse spine ; on the first pair of chelipeds only the same ventral 

 inner distal angle of the ischium is similarly but less acutely pro- 

 duced. The third pair of chelipeds is the longest of the series 

 and in adult males and large females usually extend almost to the 



