Boone, Cmstacea, Cruises of "Ara" and "Alva" 243 



The upper finger is swung obliquely, hence is the longer, being 

 the more slender of the two distally, with the entire cutting edge 

 dentate, set with thirteen to fifteen teeth, the most proximal of 

 which is the largest. 



The ambulatories are long and slender, decreasing in the 

 order 3, 2, 1, 4, the third pair being 2.3 to 2.5 times the length of 

 the carapace. Each leg has the merus unequally triquetrous, the 

 lower surface being the least, this widening distally and being 

 margined laterally by thin carinae, which also form, respect- 

 ively, the lower margins of the two lateral faces ; the dorsal sur- 

 face of the merus widens a little gradually, the two margins are 

 laminate, the lower distal angle rounded, the upper margin ter- 

 minating in an acute, subdistal tooth ; the carpus is somewhat 

 clavate, three-fifths as long as the merus, with the upper margin 

 ridge-like, paralleled by a groove, also by a second lesser ridge 

 on the dorsal upper half ; the lower margin is also laminate ; the 

 propodus is five-sixths as long as the merus, with the upper or 

 outer lateral margin carinate, a shallow, longitudinal groove on 

 the outer face, the lower lateral margin furnished sparsely on 

 the proximal half, and abundantly so on the distal portion, with 

 a dense, blackish pilosity; this brush decreasing from a distally 

 wide one on the first ambulatory to a slender one on the fourth 

 ambulatory leg. The dactyli are similar, short, triangular, very 

 acuminate distally, that of the third leg being one-third as long 

 as that of the propodus. Each dactyl has the narrowed margin 

 thickened and furnished with a dense, pilose brush of blackish 

 setae, the two halves of the outer brush being longitudinally 

 separated by a linear bare area ; the outer brush being similarly 

 separated from the inner brush by a narrow area of the lateral 

 face which bears spaced tufts of bristles. The first and fourth 

 dactyli are each about two-thirds as long as the related propodus, 

 while those of the second and third pairs of legs are, respectively, 

 one-third as long as the related propodus. 



References: Sesarma rotundata, Hess, W., in Wiegmann's A. 

 F. A., Archiv. f. Naturg., 1865, Bd. XXXI, pt. I, p. 149, pi. 6, 

 fig. 9.— MiERS, E. J., Proc. Zool. Soc. London, 1877, p. 133, 

 p. 136.— DE Man, J. G., Zool. Jahrb. Syst. Berlin, 1887, Bd. II, 

 p. 654, p. 682. 



