Boone, Crustacea, Cruises of "Ara" and "Alva" 235 



tinal regions are very definitely circumscribed, the cervical and 

 hepatic grooves being rather obscurely impressed. Tlie texture of 

 the shell is coarsely granulose; the sidewalls of the carapace 

 adjacent to the meri of the first three pairs of legs is furnished 

 with a dense pilosity. The female abdominal belt is seven-seg- 

 mented, widely oval, with the sixth somite much expanded; the 

 seventh somite almost as long as the sixth, triangulate, with the 

 slightly sinuate lateral margins converged to a rounded apex. 

 The basal antennal article is subrectangular with the narrowed 

 distal border truncate, thickened, blunt; the adjacent inferior 

 orbital margin forms a small dentate lobe. The male belt is tri- 

 angulate, as shown in plate 91. 



The external maxillipeds are close-fitting, the merus of the 

 endognath being nearly a third longer than wide, with i,he outer 

 lateral margin oblique, forming a slightly rounded, somewhat 

 obtuse angle with the anterior margin truncated, slightly convex. 



The chelipeds are those of typical Cancer, with the merus 

 trihedral, not extending beyond the carapace; the outer surface 

 of the carpus broken by four incomplete carinae, the uppermost 

 and next of which each terminate distally in a tooth. The palm, 

 which is about four-fifths as high as long, is moderately inflated, 

 the convex outer surface being traversed with seven longitudinal 

 carinae, the uppermost two of which are broken into serial denti- 

 tion along the upper margin, the next three, non-dentate carinae 

 terminating anteriorly behind the base of the upper finger, while 

 the fifth and sixth carinae are slightly heavier and traverse the 

 entire length of the palm and lower finger, terminating near the 

 apex of the latter. The fingers are a little more than one-half of 

 the length of the lower border of the palm and are partially sepa- 

 rated by a narrow hiatus, the lower finger having five or six 

 coarse teeth and the upper one three or four teeth. The black 

 colouration extends nearly three-fourths of the length of the fin- 

 gers from their apices in the females. 



The ambulatories are rather stocky, not elongated, the merus 

 triquetrous, the upper surface of the carpus traversed by two 

 longitudinal carinae, separated by a wide sulcus; the propodus 

 no longer than the carpus, not quite twice as long as wide, with 

 a longitudinal groove on the posterior lateral face; the dactyl is 

 very strong, as long as the related propodus, with the outer mar- 

 gin convex, the apex a very strong, acuminate tooth, both lateral 



