OXYSTOMATOUS AND ALLIED CRABS OF AMERICA Ig'J 



and branchial regions each bhmtly angulate. Posterior spines conical, 

 tips upturned, lateral pair two-thirds the length of median spine. 

 Front not prominent, inclined slightly upward and divided into two 

 blunt, finely granulated teeth, separated by a shallow sinus. Ptery- 

 gostomian channel projects only slightly beyond orbital margin and 

 does not exceed front; of the two notches, the outer is broad, deep 

 and U-shaped, the inner very shallow. Chelipeds about two and a 

 half times length of carapace; merus a little shorter than carapace, 

 exclusive of posterior spine, slender, cylindrical, coarsely and rather 

 densely granulate and with a blunt tooth at posterior proximal end; 

 carpus and manus finely granulate; palm narrowing distally; fingers 

 about one-fourth longer than palm, armed with about eight long, 

 slender spines at intervals, the interspaces with from nine to twelve 

 small irregular spmes. Dactyli of legs smooth, with a thin fringe of 

 hair on upper and lower margins. 



Figure il.—Iliacantha liodaciylus, male: Dorsal view. 



Measurements. — Immature male, type, length of carapace to tip of 

 median spine 17, length exclusive of spine 14.5, width 13.6 mm. 

 Adult male (tip of spine broken oft') length 28 mm, width 21.7, length 

 of right palm 16, of movable finger 16.7, length of left palm 16.6, of 

 movable finger 16 mm. 



Range. — West coast of Florida to Trinidad, West Indies; 4% to 34 

 fathoms. 



Material examined. — See table 60, p. 189. 



ILIACANTHA HANCOCKI Rathbun 



Plate 57, Figures 1, 2 

 Iliacantha hancocki Rathbun, Proc. BioL Soc. Washington, vol. 48, p. 2, 1935. 



Type locality. — Santa Maria Bay, Mexico; 35 to 40 fathoms; 

 Hancock Galapagos Expedition; 1 male is type (U.vS.N.M. no. 69260). 



Diagnosis. — Allied to /. liodaciylus. Dift'ers in its shorter median 

 spine, shorter and stouter chelipeds, terminal segment of male abdo- 

 men triangular. 



80232—37 13 



