A«T. 6 ^EW EOCENE CRABS FEOM TEXAS — RATHBUN O- 



mediate marginal granules are of important size, almost tubercles. 

 The surface is more even than in the smaller females. The right 

 cheliped is present and the stumps of three ambulatory legs (pi. 3, 

 fig, 1). Cheliped massive, its chela as long as the carapace is wide. 

 Surface of carpus and chela coarsely granulate. Carpus (pi. 3, 

 fig. 2) a little longer than wide; on the upper side a shallow groove 

 runs parallel to the distal margin. Chela strongly curved both cross- 

 wise and lengthwise following the conformation of the lower surface 

 of the body. Palm (pi. 3, fig. 1) increasing rapidly in height from 

 the proximal to the distal end, but not attaining a height equal to 

 its length. The outer surface is bent strongly over horizontally to 

 form an upper surface (pi. 3, fig. 2) ; the lower margin is very con- 

 cave, accented by the strongly deflexed finger. Outer surface (pi. 3, 

 fig. 1) with a high conical swelling (s) opposite the iuterdigital sinus 

 and further back from the margin than in the female; of the three 

 proximal tubercles only the uppermost (r) is preserved, a short 

 longitudinal ridge highest at its middle and sloping down to either 

 end. Upper surface of palm (pi. 3, fig. 2) oblique and convex in both 

 directions except at the distal end, where there is a depression; its 

 inner margin is marked by a row of four large tubercles on the proxi- 

 mal half and a suggestion of two others on the distal half ; its outer 

 margin has near the middle three or four small and very low tuber- 

 cles. Fingers very broad at the base where they meet when closed, 

 but rapidly tapering to long, narrow, thick fingers, broad-oval in 

 cross section, Avith subacute tips. Each finger (pi. 3, fig. 1) has at 

 base on the occludent margin a large conical tooth or tubercle, the 

 dactylar tooth folding within or proximal to the ^Dropodal tooth. 

 Near the middle of the dactylus is a similar though smaller tooth; 

 extremity of immovable finger unknown. The stump of the merus of 

 the left cheliped suggests that the latter was much smaller than the 

 right cheliped. The merus of the ambulatory legs is long and nar- 

 row, the cross section narrow-oval. 



Paratype d: Distal half of dactylus of a larger male chela than 

 any preserved showing a part of the large tooth at middle (pi. 3, 

 fig. 5t. Paratype e: A much worn left palm of medium size with 

 stumps of fingers. The remoteness of the large tubercle from the 

 fingers indicates a male. Paratype /.'A piece of a left cheliped com- 

 prising merus and carpus (pi. 3, fig. 3) ; the former is short and 

 stout, not quite so high as long, its margins bluntly rounded except 

 at the proximal end of the lower outer margin, Avhich is drawn to a 

 thin, sharp edge (t). The subtriangular outer surface of the carpus 

 ends proximally in a projecting point (/?). Sex indeterminable. 



H. americanus, the first species of the genus to be described from 

 the American continent, resembles several European species. In its 



