494 PROCEEDINGS OF THE NATIONAL MUSEXJM vol. 91 



occasion in places apparently three rows) of closely set corneous 

 scales for at least half the length of the free portion of the rostrum, 

 beyond the midpoint there is but a single row of the scales, which, 

 like the carina, tends to fade out or disappear before reaching the 

 distal extremity of the rostrum (sometimes there is an odd grouping 

 of a few scales on the dorsum of the extreme tip of the rostrum) ; 

 the rostral carina is plainly marked backward to the level of the 

 anterior margins of the protogastric lobes, and in at least the larger 

 of the specimens at hand,, faintly to be seen if only as an interruption 

 to reflected light halfway back to the cervical groove. 



Protogastric lobes poorly indicated; epigastric prominences not 

 very prominent, obliquely elongated, scabrous swellings. 



Orbital sinus moderately wide, in dorsal view appearing not much 

 wider than deep ; orbital spine always present, small but well formed ; 

 extraorbital sinus narrow, a V-shaped notch. Anterolateral spines 

 relatively small, yet reaching past posterior border of cornea often 

 about or nearly to middle of its length. Anterolateral angle of first 

 hepatic lobe produced but not spined, though scabrous or small 

 spinulated as on lateral margin of lobe; second and third lobes no 

 more than plainly indicated by shallow emarginations in lateral 

 margin of anterior portion of carapace. 



Asymmetry of hands not very pronounced ; large hand of moderate 

 size, more or less subovoid, only moderately inflated; the hands are 

 coarsely scabrous, almost tuberculated. Movable finger in the type 

 does not seem to have a real lobe developed on outer margin near 

 base, yet there are a few larger spinules on a very slight elevation at 

 the site of the lobe found in other species; however, in other speci- 

 mens smaller than the type a slight lobe armed with several sharp 

 spinules seems definitely present. Palmar crest more or less nar- 

 rowly subrectangular, fairly thin-edged, serrate or notched, and 

 spinulose ; dorsal surface of crest at most only very slightly concave, 

 margin of crest not noticeably or appreciably, if at all, bent upward. 



Ridge of carpus above spined inner margin carrying practically 

 a double row of scabrous elevations; between anterior spine, the 

 largest of the series arming the inner margin of the carpus, and the 

 carpal ridge there is a short, acute, conical spine nearly subequal 

 in elevation with the scabrosities of the carpal ridge (this spine seems 

 to be present in the specimens from the type locality,, Arroyo, but 

 not at all, or only almost imperceptibly indicated in the specimens 

 from Covunco) ; anterior internal lobe or angle of carpus flattened- 

 conical, or triangular, armed with one larger, sharp-pointed corneous 

 denticle, with a smaller one close behind on the posterior slope, and 

 usually one or more still smaller spiniform scales. Upper longi- 

 tudinal margin of merus of cheliped with a series of small, more or 



