THE SPIDER CRABS OF AMERICA 97 



Chelipeds nearly twice as long as carapace, granulate, margins 

 spinous; manus swollen; fingers more than half the length of palm, 

 gaping, though narrowly, for two-thirds their length. Ambulatory 

 legs granulate, with tufts of curled setae and often small spines. 



Variations. — In the northern part of its range where the species 

 occurs in greatest abundance, the dorsal protuberances are very 

 short, usually tubercles or sometimes short truncate spines; the 

 postorbital projection is rather broad, triangular, dentiform; the 

 margins of the merus of the chelipeds are irregularly granulate; the 

 legs are granulate, not spinulous. This form is designated as 

 Euprognatha rasteJlifera marthae, new subspecies. 



Among the Florida Keys which is the type region for the species, the 

 four dorsal protuberances are each surmounted by an undoubted 

 spine of medium length, capitate; the postorbital projection is nar- 

 rower and the spines of the frontal region slenderer than in the north- 

 em form; the merus of the chelipeds is somewhat rougher; the legs 

 are finely and sparingly spinulous. 



The most southern form (Havana, Porto Rico) has longer, slenderer 

 and sharper spines; surface of carapace more closely and finely 

 roughened; spines bordering the merus of the chelipeds well developed; 

 legs more spinulous; carapace a little narrower and higher and the 

 regions more deeply separated than in more northern forms. This 

 form is E. rasteJlifera acuta.] 



None of these forms is entirely restricted to its own range, they 

 overlap one another, and two forms may occur in the same haul. 

 (See table, pages 98-101.) 



The specimen of rastelWera figured by A. Milne Edwards ^^ is a 

 typical one, but the roughness of the merus of the cheliped is not 

 indicated. The subspecies marthae was described and figured by 

 S. I. Smith, 1881 to 1886.^* I am unable to say whether inermis 

 should rank as a subspecies or not; it may be identical with marthae. 



Measurements. — Male, holotype of marthae (18749), length of 

 carapace 14.3, width 11.6 mm. Typical male rastellifera (55482), 

 length 9.8, width 7 mm. Male, acuta, holotype of spinosa (18108), 

 length of carapace 9, width 6.8 mm. The length is measured to the 

 tip of the rostral teeth. 



Range. — From off Nantucket Island, Massachusetts, to Straits 

 of Florida, southern part of Gulf of Mexico, and Caribbean Islands, 

 as far as Grenada and Barbados. Depth, 15 to 387 fathoms. 



Material examined. — See table, pages 98-101 



" Crust. Reg. Mex., 1879, pi. 33, figs. 2-2<'. 



"Proc. U. S. Xat. Mus. vol. 3, 1880 (1831), p. 41.5, and vol. 6, 1883, p. 9; Rept. U. S. Fish Commr. for 

 1882 (1884), p. 347, pi. 1, figs. 3 and 3a, and for 1885 (1886), p. 621. 



