246 Bulletin Vanderbilt Marine Museum, Vol. VII 



elevated, smooth, except for coarse punctae, the lateral margins 

 defined carina-like anteriorly, this terminating in a small denti- 

 cle anteriorly. The sidewalls are high, the pterygostomian region 

 covered with a short, coarse, thick pilosity. There is a small, tri- 

 angular, trihedral process between the orbit and the outer an- 

 tennae. The first article of the external antenna is subrectangu- 

 lar, distally truncate ; the second article is small, distally sinuate, 

 not quite touching the front. 



The chelipeds, moderately unequal in this old male specimen, 

 have the merus trihedral, the carpus with the upper surface 

 roughly four-sided, with a sharp, wide triangular tooth at the 

 inner distal angle (this angle being less conspicuous on the 

 smaller cheliped ; the propodus is as long on the lower margin as 

 the greatest height of the palm, the outer surface being moder- 

 ately convex transversely; with the lower dactyl two-thirds as 

 long as the lower margin of the palm, triangular, with one large 

 tooth and two or three smaller ones on the distal half ; the upper 

 dactyl is longer, slenderer, swung obliquely, with the outer mar- 

 gin convex, the cutting edge separated by a wide oval hiatus from 

 the lower finger, the blunted apices only meeting ; a single median 

 tooth and several rudimentary denticles distally. The opposed 

 smaller propodus and finger are similar except in size, the hiatus 

 being distinctly narrower and the teeth all very small or absent. 



The ambulatories are strong, stout, the distal four articles 

 being very abundantly furnished with bristles, these being placed 

 on all three edges of the trihedral merus, one dorsal and two ven- 

 tral; also in three longitudinal series on the upper face of the 

 carpus ; on the dorsal and ventral margins of the propodus, and 

 on the dactyl, which is one and one-half times as long as the pro- 

 podus, has the outer margin flat, armed with a double series, each 

 consisting of ten to twelve sharp spines, the two rows being sepa- 

 rated by a linear groove bearing tufts of bristles ; the inferior 

 margin of the dactyl is similarly flat, with a double series of 

 spines separated by a median groove set with bristles ; the apex 

 is strong, sharp, nail-like. 



References: Cardisoma hirtipes, Dana, J. D., Proc. Acad. 

 Nat. Sci. Phila., 1851, p. 253; in Wilkes, C, U. S. Explor. 

 Exped., 1838-42, Crust., 1851, vol. XIII, p. 376, atlas, for 

 vols. XIII-XIV, pi. 24, figs. 2-a-d.— Milne Edwards, H., 



