^"'siw!^''] PKOCEEDING.S OF THE NATIONAL MUSIUIM. 653 



at the cervical suture and between that suture an<l the orbital an^le. 

 Merus of maxilliped more (quadrate, less tria,iisj;ular than in the i)rece(l- 

 iii^y s])ecies. Inferior regions of the caraijaee very linely j;raiiulate and 

 punctate, cervical suture present. Jugal area pubescent as far back 

 as the sternum. Small cheliped (the only one i)resent) granulate, 

 punctate, with a broad merns; inner face outlined below and distally 

 with Ijead-like tubercles, inner inargin with a double row of blunt 

 spines, increasing in size distally, upper margin with sjunulous ruga^. 

 extending on the outer surface distally. Carpus Avith a very shallow 

 sulcus, a short inner spine; inner margin spinulous. Upper and lower 

 margins of hand sub[)arallel; lingers in contact. The merus Joints of 

 the ambulatory legs are flattened, widening toward the center, den- 

 ticulate above; carpal and propodal joints spinulous on the upper, 

 inner, and distal margins. 



Length, about 29; width, 41); length of smaller cheliped, about 01""". 



? Mexico, JolmXantus; a single mutilated specimen, 9 (2527). 



This specimen is labeled "Cape St. Lucas", but it is more likely to 

 have come from the vicinity of Manzanillo or Colima, whei'e Mr. Xantus 

 made valuable collections of fresh- water fishes and moUusks in 1862. 



A'". Front vcrticallj' dellexed, foruiiiig au acute lamellate crest. 



Pseudothelphusa colombianus. 



(PI. Lxxiv. Fig. 10; PI. Lxxv, Fig. 1.) 



Carai)ace slightly convex, finely punctate, granulate anteriorly and 

 near the lateral margins, the granules more evident in the smaller 

 specimen. P]pigastric lobes very iirominent, the ridge continued faintly 

 for a short distance in a transverse line of granules. Cervical suture 

 curved, becoming less marked near the lateral margin. Superior 

 frontal margin lamellate, almost straight, tuberculate, divided by a. V- 

 shaped notch at the extremity of the median sulcus. The margin near 

 the orbit turns nearly parallel to the orbital margin and terminates Just 

 above the base of the eye. Inferior frontal margin slightly in advance 

 of the superior, sinuous, with a prominent, horizontal, ridged, and granu- 

 late margin, which is continuous with the tuberculate or crenulate or- 

 bital margin. Front deepest at the ouf er ends. Anterolateral margins 

 denticulate, interrupted by a shallow sinus at the cervical suture and 

 another between that and the orbit. External orbital fissure small and 

 shallow, formed by the absence of one or two granules. Inferior surtac^e 

 of the carapace finely granulate near the margin. Jugal region pubes- 

 cent and anteriorly granulate. Chelipeds of female unequal, punctate. 

 Smaller cheliped nuich like that of xantu.sl, but with few granules; the 

 inner margin lias a singh'row of spines, and below it a row of tuber- 

 cles. Larger cheliped similar to the smaller, except that the propodus is 

 much deeper (PI. lxxv, Fig. 1). Fingers in contact when closed. Am- 

 bulatory legs little com[)ressed ; meral joints widening toward i)roximal 

 end, denticulate on upper margin, and in the last pair prominently ridged 



