OXYSTOMATOUS AND ALLIED CRABS OF AMERICA 257 



OSACHILA ACUTA Stimpson 



Plate 79, Figures 1, 2 



Osachtla acuta Stimpson, Ann. Lye. Nat. Hist. New York, vol. 10, p. 114, 1871 

 (type localities, Panama and Manzanillo; types not extant). 



Diagnosis. — Rostrum with thin, sharp, denticulate margin. 

 Posterolateral margin bearing two strong triangular teeth, one next 

 the lateral tooth, the other next the posterior extremity. Outer 

 surface of manus with five longitudinal ridges. 



Description. — Protuberances of carapace rather small, somewhat 

 conical, tuberculated, and coarsely punctate; between them the 

 surface is smooth, naked, and microscopically and crowdedly punctate. 

 Rostrum flat, narrow, prominent, bilobed. Anterolateral margin 

 with generally seven or eight teeth behind the point where the 

 transverse subhepatic ridge joins the margin; the teeth increase in 

 size posteriorly, each composed of two or three denticles, the median 

 one largest where there are three. Posterolateral margin thickened 

 as if double, and irregularly tuberculated and bidentate. The 

 posterior extremity of the carapace is narrow, with two thickened 

 tuberculated margins placed one above the other. Of the ridges on 

 the outer surface of the hand, the upper three are formed of large 

 tubercles, the lower two of small ones ; superior crest with three equal 

 teeth. 



Color. — Yellowish, with spots of red and white resembling patches 

 of lichen. (Stimpson.) 



Measurements. — Male type, length of carapace 17.9, width 21 mm. 



Range. — Manzanillo, Mexico, to Panama (Stimpson); Darien 

 (NobiU); Ecuador. 



Material examined. — La Libertad, Ecuador ; dredged north of Point 

 St. Elena; 8-10 fathoms; February 9, 1934; station 209, Hancock 

 Galapagos Expedition; 1 small male (69619). 



OSACHILA LATA Faxon 



FiGTTRE 45; Plate 78, Figures 1, 2 



Osachila lata Faxon, Bull. Mus. Comp. Zool., vol. 24, p. 159, 1893 (type locality, 

 Western Mexico, 80 fathoms; type in M. C. Z.); Mem. Mus. Comp. Zool., 

 vol. 18, p. 32, pi. 5, figs. 2-2b, 1895. 



Diagnosis. — Carapace expanded laterally; length : bread th= 3 : 4. 

 Two transverse rows of low tubercles on hinder part of carapace 

 anterior to hind margin. 



Description. — Three low obtuse gastric protuberances, one cardiac, 

 three or four branchial ; the surface of all tuberculate tubercles coarsely 

 punctate, as also the surface between protuberances. Frontal lobes 

 thick, punctate. Anterolateral margin sharp; behind the point where 

 the subhepatic ridge joins this margin it is divided into five obtuse, 



