282 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



more advanced than the inner supra-orbital tooth but less advanced 

 than frontal teeth. 



Ischium of outer maxillipeds with a deeply impressed longitudinal 

 line at its inner two-fifths; merus as broad as long. Chelipeds very- 

 unequal in both sexes; a deep subdistal indentation on upper margin 

 of merus and a corresponding low tooth; a short subacute tooth at 

 inner angle of wrist; palms inflated, fingers considerably shorter 

 than middle length of palm, gaping; the dark color of fingers covers 

 the dactyl except at its base and barely covers the fixed finger; 

 prehensile teeth white. Dactyls of ambulatory legs clothed, ex- 

 cept in the longitudinal furrows and the horny tips, with a short 

 felt; also a fringe of longer hair on the lower margin. 



Young. — Two young, the largest only 11.3 mm. wide from La 

 Paloma, have the front double-edged, the edges granulate and sepa- 

 rated b}^ a deep groove; the lobes are subtruncate and slightly concave 

 but scarcely bilobed, although the inner part of the lower lobe projects 

 slightly beyond the upper edge. In all other characters these speci- 

 mens resemble adult crenulatus. The probability is, therefore, that 

 the lower edge of the front in the young becomes the true thick edge 

 in the adult, and that the upper edge in the young is represented in 

 the adult by the row of coarse granules just behind the front which is 

 set off by an inconspicuous groove corresponding to the deep marginal 

 groove in the young. A series of sizes intermediate between 1 2 and 

 40 mm. in carapace width is needed to confirm this surmise. 



Color. — Dried male (57124), dark carmine above, light buff below, 

 ambulatory legs and hind part of carapace dotted with light buff; 

 fingers nearly black. 



Measurements. — Male (57124), total length of carapace 50.8, width 

 of same 74.2, fronto-orbital width 23.2, front 12.3 mm. Young male 

 (60972), total length of carapace 8.7, width of same 11.3, fronto- 

 orbital width 6.1, width of front 3.1 mm. > 



Range. — Uruguay to Patagonia. 



Material examined. — 



URUGUAY.— Coronilla Island; beach; 1922; Hugh M. Smith; 

 1 major chela (57692). 



Cabo Polonia, Rocha; F. Felippone; 3 males, 2 females and 3 major 

 chelae of larger specimens (55569, 56689, 57124). 



Cabo Santa Maria, Rocha; F. Felippone; 1 male (57574), 1 female 

 (54635), 1 female (61379). 



Puerto La Paloma; December 6 and 7, 1925; W. L. Schmitt; 19 

 specimens (60964, 60965). March, 1925; Atair; 1 young, lent by 

 Buenos Aires Mus. (15412), 1 young (60972). F. Felippone; 1 male, 

 1 ovigerous female (61378). 



Punta del Este, Maldonado; 1922; F. Felippone; 1 male (57123). 



Montevideo; F. Felippone; 1 male (55174). 



