386 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



MITHRAX (MITHRAX) ROSTRATUS Bell 



Plate 255 



Mithrax rostratus Bell, Proc. Zool. Soc. London, vol. 3, 1835 (1836), p. 171 

 (type-locality not given; type not extant) ; Trans. Zool. Soc. London, vol. 2, 

 1836, p, 51, pi. 10, figs. 1-16. — A. Milne Edwards, Crust. R6g. Max., 

 1875, p. 101. 



Diagnosis. — Size medium. Carapace tuberculate and spinous; 

 without lateral angle. Wrists covered with warty tubercles. 



Description (after Bell). — Carapace rounded, anteriorly produced) 

 moderately elevated, regions distinct; surface granulate and tubercu- 

 late, and with the margins and outer part of the branchial regions 

 spinous. Rostral horns elongate, apices curved inward. Orbit 

 nearly circular, surrounded with warty tubercles. Antennae rather 

 longer than rostrum; basal joint with a tuberculated tooth at its 

 outer angle; second and third joints rather broad, with long hairs 

 on each side; fourth joint cylindrical and elongated. 



Chelipeds of male moderately robust, of female rather slender; 

 movable finger in male with a tubercle near base; hand smooth, 

 other joints spinous and tuberculated. Legs spinous and tubercu- 

 late, excepting on the last two joints which, like the others, are 

 hairy; dactyls of male furnished with a series of small denticulations 

 beneath; female without them. 



Color. — Lightish brown; hands mottled. 



Measurements. — Length of carapace, 2 inches 2 lines (about 53 

 mm,), including rostrum which is 4 lines (about 10 mm,) long and 

 2 lines broad; width of carapace nearly 2 inches. 



Locality. — Bell describes this species among a lot of " Crustacea of 

 the Coasts of South America." A. Milne Edwards thinks that it is 

 probably from the Galapagos Islands, It has not been collected 

 since the original description. 



MITHRAX (MITHRAX) CORNUTUS Saussure 



Plate 137, figs. 3 and 4; plate 256 

 CORAL CRAB; RED SPIDER CRAB (Verrill) 



Cangrejo espinoso Parra, Descripcion de diferentes piezas de historia natural, 



1787, p. 127, pi. 47, fig. 1. 

 Mithrax cornutus Saussure, Rev. et Mag. Zool., ser. 2, vol. 9, 1857, p. 501 



(type-locality, Antilles; cotypes in Geneva Mus.); Mem. Soc. Phys. 



Geneve, vol. 14, 1858, p. 423 [7]. — A. Milne Edwards, Crust. Reg. 



Mex., 1875, p. 97, pi. 22.— Miers, Challenger Rept., Zool., vol. 17, 1886, 



pp. 86 and 87. — Verrill, Trans. Conn. Acad. Arts and Sci., vol. 13, 1908, 



p. 400. 



Diagnosis. — Antero-lateral spines not all in the same line, the last 

 one situated at lateral angle of carapace. Three spines on basal 

 antennal article. Three or four spines on supraorbital margin ex- 



