Boone, Crustacea, Cruises of *' Eagle" and " Ara," 1921-28 165 



The first legs are decidedly unequal in the female, the left being the 

 larger. It has the merus elongate, slightly convex, laterally com- 

 pressed ; the carpus short, convex, distally cup-like ; the propodus, in- 

 cluding the finger, as long as the carapace, convex, moderately swollen 

 proximally, less so distally ; the propodal finger is represented by the 

 blunted, excavated end of the propodus, into which the dactyl fits; 

 there is a thin, convex lateral margin fitting closely upon each side 

 of the proximal part of the dactyl. The dactyl is short, swings hori- 

 zontally, fitting the concave propodal finger. The shape of the dactyl 

 is best understood by an examination of the attached figures which 



J 



Text fig. 5. — Large claw of Alpheus vanderbilti Boone, greatly enlarged, 

 sal view. B. Profile. C. Ventral view. 



A. Dor- 



show its exact contour. There is only one tooth on the dactyl, whereas 

 that of C. cylindricus is said to have "two or three." The smaller 

 cheliped has the meral and carpal joints similar to those of the larger, 

 and the propodus is as long, but it is slenderer, with the palm convex, 

 tapering a little distally, about three-fourths as long as the fingers, 



