THE SPIDER CRABS OF AMERICA 389 



there is also a small, rectangular tooth on the outer margin, close to 

 the orbit. The orbit is armed with one spine below, outside the 

 antenna, one at outer angle, and three above, of which the prominent 

 preorbital spine is one.^^ Four large antero-lateral spines and one 

 posterolateral; the first, or hepatic, spine is double, having a small 

 spine on its anterior side; the next three antero-lateral spines have 

 each a small spine in front of it; the last of these antero-lateral 

 spines is the longest and is situated at the lateral angle of the carapace, 

 below the level of the others; the postero-lateral spine is shorter than 

 the four antero-lateral. 



Chelipeds of male about as long and as stout as the legs of the first 

 pair; merus spinous, with two rows of long spines above; carpus 

 covered with short, conical, subacute spines or tubercles, three of 

 which are on the inner margin; manus with one or a few spinules 

 above near proximal end; these are evident only in larger specimens, 

 scarcely a trace in those with a carapace-length less than 18 mm.; 

 fingers with a short and narrow gape, edges denticulate, a larger 

 denticle on the dactylus in the middle of the gape. The spines on the 

 legs are arranged in two rows above on the merus and carpus and are 

 especially long in the first two pairs. 



Color. — General color, deep red orange. Fingers somewhat purplish 

 red with narrow white bands near bases (Henderson). 



Measurements. — Male (25592), total length of carapace 21, length 

 without horns 18.2, width without spines 15.8, width with spines 18 

 mm. Largest specimen, male (46964), total length 24, without horns 

 20.5, width Avithout spines 17, with spines about 20 mm. 



Range. — Gulf of Mexico (west coast of Florida) ; Florida Keys from 

 Miami westward; Yucatan Channel. Porto Rico, Santa Cruz, 

 Flannegan Passage, Montserrat and Grenadines (A. Milne Edwards 

 for Nemausa rostrata). Off Bahia, Brazil. Depth, 12 to 45 fathoms; 

 to 163 fathoms (A. M. E.). 



Material examined. ^° See table, page 390. 



RemarJcs. — M. acuticornis, of which no large specimens have yet 

 been reported, may very easily be confused with the young of M. 

 cornutus and M. spinosissimus. The body of spinosissimus, young, is 

 rounder than in the other two species; the gastric region is less 

 imeven in cornutus, young, and its granulation finer, sharper and less 

 regular; rostrum of acuticornis shorter than in specimens of equal 

 size of the other two species. The other notable dift'erences are 

 tabulated below (p. 391). 



« Stimpson in his description gives six spiniform teeth to the orbit, not including those of the antennal 

 joint, but this appears to be an error. 



»« As this small species has in the past been confused with the young of other species, only such specimens 

 are included in the table as have been subject to careful revision. 



