384 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



Gelasimus hcterophthalmus Smith, Trans. Connecticut Acad. Arts and ScL, 

 vol. 2, 1870, p. IIG, pi. 2. figs. 6 and 6a; pi. 3, figs. 1-16 (type-locality, 

 Gulf of Fonseca ; type in Mus. Comp. Zool. ) , 



Vcn platydactyla, var. stylifera Oktmann, Zool. Jahrb., Syst., vol. 10, 1897, 

 p. 347 (part). 



Diagnosis. — Front very narrow, spatuliform. Ocular stylet pres- 

 ent, longer than peduncle. Oblique ridge on inner surface of palm 

 continued by a right angle to upper margin. Pollex with strong 

 tooth on basal half. 



Description. — Width of carapace from one and two-fifths to one 

 and three-fourths times its length. Dorsal surface smooth and shin- 

 ing, convex longitudinally but not at all laterally. Sulci shallow. 

 Superior border of orbit subentire, strongly arcuate in the middle, 

 outer angle strongly produced laterally on the side of the large 

 cheliped but not on the other. Only the posterior part of the lateral 

 margin is indicated by a faint, granulous line. Front spatulate; the 

 upper margins of the orbits form a narrow, triangular median inter- 

 space. Inferior border of the orbit denticulate with shallow, flat- 

 tened, truncate teeth. The ocular peduncle on the side of the large 

 cheliped is terminated beyond the cornea by a very slender filiform 

 stylet much longer than the peduncle itself, and slightly flattened and 

 expanded at the tip. No trace of a terminal stylet on the peduncle 

 of the other side. 



Inner margin of merus of larger cheliped armed with a low crest, 

 which may be slightly dentate at its distal extremity; outer margin 

 sharp and denticulate. Carpus tuberculous. Basal portion of pro- 

 podus coarsel}' and densely tuberculous, margins thin and dentate; 

 inner surface smooth, with a rectangular, transverse ridge. Fingers 

 long, compressed and high, smooth inside, prehensile edges evenly 

 tuberculated and each armed with a single stout submedian tooth, that 

 on the pollex considerably within that on the dactylus. Fingers 

 gaping in basal half. Outer surface of pollex rough with irregular 

 shallow punctures, lower edge granulous, with a submarginal granu- 

 lous line. Dactylus smooth outside except near the base, uppel 

 edge subentire. 



Ambulatory legs smooth and unarmed. 



Measurements. — Male (cotype of heterofhthalmus) ^ length of 

 carapace 18.7, width of same 32.2 mm. 



Range. — Gulf of Fonseca, Salvador, to Guayaquil, Ecuador. 



Material examined. — 



Gulf of Fonseca, Salvador; J. A. McNiel; 4 males, cotypes of 

 heterophthalmus (M. C. Z.). 



Puntarenas (Pacific Ocean or Estero side), Costa Eica; Feb., 1905; 

 J. F. Tristan; 2 males (32325: 



