THE GEAPSOID CRABS OF AMEEICA. 297 



SESARMA (SESAEMA) OPHIODERMA Nobi!i. 



Sesai'ma {Scsarma) ophiodcrma Nobili, Boll. Miis, Zool. Aiuit. Coinp. R. 

 Univ. Torino, vol. 16, No. 415, 1901, p. 44 (typo-localit.y, Esnieraldas, 

 Ecuador; liolotype, young female, in Turin Mus. ). 



Diagnosis. — Length and width of carapace equal. Front half as 

 wide as carapace, its superior lobes forming a convex arch. Two 

 lateral teeth. 



Description. — Greatest Avidth of carapace is near insertion of sec- 

 ond pair of ambulatory legs and is equal to the length. Carapace flat ; 

 entire surface rough with rather large, robust granules; branchial 

 regions bounded by a deep sulcus: mesogastric sulcus narrow, deep, 

 reaching frontal lobes. Front one-fourth as high as wide, defiexed 

 vertically and bordered on its lower margin by a very prominent 

 crest, which in the middle is deeply emarginate; vertical surface 

 concave and ;?ather smooth. Frontal lobes disposed in a convex 

 curve, not straight as in most of the Sesarmas ; the lobes are subequal, 

 those of the lateral pair slightly larger, but instead of being in a 

 straight line, those of the median pair are con^-ex and very prominent 

 when seen from below ; the margin of the lobes is without granulation 

 other than that common to the rest of the surface. Outer orbital 

 tooth short, inclined a little forward and outward; behind this 

 tooth are two minute teeth or rudiments of teeth of which the second 

 is the better developed. 



Chelipeds very slender; merus rugose outside, its three margins 

 denticulate, the inner one with a small dentiform projection toward 

 the apex; carpus without inner projection, its surface coarsely granu- 

 lous; manus somewhat convex outside, clothed with very distinct and 

 rather acute granules, inner surface apparently smooth, upper mar- 

 gin little accented, more distinct in the male than in the female; 

 digits longer than palm, teeth rather large, apices corneous and 

 excavated. 



Legs long and slender ; merus externally rugulose, length two and 

 one-half times width, upper margin bearing a strong acute spine, 

 lower margin unarmed ; length of propodus about one and one-half 

 times that of dactylus, the latter slender and long-acuminate; both 

 have a few setae at the end. 



Color. — General color, olive-brown ; legs olive-gray annulated with 

 brown. Fingers of cheliped orange. 



Measurements. — Female holotype, lengtii of carapace 9, width of 

 same 9, exorbital widtli 8.7^, width of front -l.."), height of same 1 

 mm. (After Nobili.) 



Range. — Known onh^ from the type-specimen from Esnieraldas, 

 Ecuador. 



