THE SPIDER CRABS OF AMERICA 399 



Range. — From Mazatlan, Mexico, to Panama. 



Material examined. — Mazatlan, Mexico; A.Agassiz; 2 males (2102^ 

 M. C. Z.). 



Puerto Angel, Oaxaca, Mexico; 1910; C, R, Orcutt; 1 female 

 holotype (47110). 



Mexico; T. B. Wilson collection; 1 female (Phila. Acad.). 



Panama; Captain Field; 1 male, 2 fem.ales (Phila. Acad.). 



Remarlcs.—'Yhi'& is undoubtedly very near M. armatus. In armatiis, 

 the palm is entirely smooth, according to Saussure, who reiterates 

 the statement; and two of the large lateral spines are postero-lateral, 

 according to his figure, instead of the fourth spine being at the widest 

 part of the carapace. 



MITHRAX (MITHRAX) ARMATUS Saussure 



Plate 262, fig. 6 



Mithrax armatus Saussure, Rev. et Mag. de Zool., ser. 2, vol. 6, 1853, No. 8, 

 p. 418 [2], pi. 13, fig. 1 (type-locality, Mazatlan, Mexico; type in Geneva (?) 

 Mus.). — A. Milne Edwards, Crust. R6g. Mex., 1875, p. 101. 



Diagnosis. — Size medium. Carapace without lateral angle, but 

 with 5 lateral spines. Dorsum tuberculate. Horns little divergent. 



Description (after Saussure). — Body covered with stiff hairs. Cara- 

 pace, exclusive of rostrum, as wide as long, rhomboid, a little rounded 

 behind. Rostral horns elongate, slightly divergent, tips curving 

 inward, outer margin rugose. Orbits bordered by strong spines, the 

 antennal spine long, acute, recurved at the tip, rather remote from 

 the orbit; supraorbital spine stout and blunt; besides, on the outer 

 border there are 2 tubercles separated by small fissures. Lateral 

 margins of the carapace armed with 5 long spines, the anterior of 

 which has a smaller spine joined to it on the inner side; fifth spine 

 postlateral. Numerous small spines on the inferior portions of the 

 carapace. Grooves outside the gastric and cardiac regions strong. 

 Entire carapace covered with small rounded tubercles and some 

 larger ones disposed in regular order (see figure). 



Manus of female long, smooth. Legs very spinous above, spines 

 long, arranged in 2 rows; carpal joints without spines. 



Color. — Obscure yellow. 



Measurements.— Female, holotype, total length of carapace 1^ 

 French inches (47.3 mm.), length of rostral horns 3}i lines (7.3 mm.), 

 greatest width of carapace 1^ French inches (42.8 mm.). (Saussure.) 



Locality. — Mazatlan, Mexico. Kjiown from the type-specimen 

 onlv. 



