394 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



Diagnosis. Oblique ridge inside hand continued toward upper 

 margin. Front very broad and shallow. Merus joints of legs not 

 enlarged. 



Description. Carapace convex, minutely punctate and granulate, 

 branchial regions more or less plainly marked with small tubercles 

 near the outer edge; -shaped impression deep, a faint longitudinal 

 groove on branchial regions; groove behind orbital margins. Front 

 broad, about one-third width of carapace, little produced. Lower 

 edge of eyebrow with a strong convexity midway between the front 

 and lateral angles. These last are almost right angles and slightly 

 or not at all produced forward. Lateral margins of carapace for a 

 short distance nearly parallel, arching slightly outward, and then 

 converging quite strongly to the posterior margin. 



Merus of large cheliped of male marked outside with transverse, 

 sparingly setose striae; carpus long, roughened with small blunt tu- 

 bercles; hand large and stout, nearly twice as long as width of cara- 

 pace, upper surface with small tubercles which gradually become 

 smaller further down on the outer surface; lower side of the palm 

 marked with a fine raised line which fades out on the base of the 

 pollex. Inner surface of palm marked with a short, very prominent, 

 tuberculated ridge which runs from near the lower margin toward 

 the supero-proximal portion of the hand; from the upper end of 

 this ridge there is a short tuberculated ridge extending toward the 

 base of the dactyl; the prominent lower margin of the carpal groove 

 extends backward from the angle where these ridges meet, in the 

 same direction as the upper ridge; the meeting point of the 3 ridges 

 forms the apex of a large, high, three-sided pyramid. Pollex gently 

 curved, prehensile edge with a few teeth on distal half, tip truncate; 

 dactyl curving from near the middle, overreaching the pollex and 

 bearing a few prehensile teeth. Ambulatory legs slender and hairy. 

 (Abridged from Holmes.) 



Color. Carapace in alcohol dark olivaceous (Holmes). 



Measurements. Male (43352), length of carapace 19.5, width of 

 same 28.6 mm. 



Habitat. Very abundant in the woods 2 kilometers from the sea- 

 shore (Tristan). Found also in fresh water and at Todos Santos in 

 a lagoon. 



Range. Lower California to Panama. 



Material examined. 



Cape St. Lucas, Lower California; John Xantus; 1 female 

 (M. C.Z.). 



Acapulco, Mexico; Hassler Exped. ; 3 males (M. C. Z.). 



Boca del Jesus Maria, Costa Rica: Apr. 22, 1905; P. Biolley and 

 J. F. Tristan; 1 male (32323). J. F. Tristan; 1 male. 1 female 

 (32324). 



