150 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



basal protuberance which is much smaller than in the type and is 

 directed not distad but normal to the article; the tubercle is smallest 

 on the second ambulatory and largest on the fourth. The rostrum 

 is faintly bilobed at tip. The anterior margin of the hepatic region 

 slopes backward and outward and bears a small tubercle not far 

 from the antero-lateral angle; the outer or anterior margin of the 

 branchial lobe likewise has a tubercle about the same distance from 

 the postero-lateral angle. These characters may represent age 

 variations. 



EPIALTUS SULCIROSTBIS Stimpson 



Plate 46, fig. 3; plate 47, fig. 2 



Epialtus suldrostris Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, 1860, 

 p. 198 [70] (type-locality. Cape St. Lucas; cotype in Paris Mus.). — A, 

 Milne Edwards, Crust. R^g. Mex., 1878, p. 141, pi. 27, figs. 6-66. 



Diagnosis. — Rostrum thick, simple, tip spiniform below. Crest on 

 hand laminiform. 



Description. — Carapace nearly or quite as wide at hepatic as at 

 branchial regions; hepatic angles squarer and more prominent than 

 in E. hituherculatus. No postorbital tooth; a prominent preorbital 

 lobe on which is a small tooth and in front of which the rostrum 

 abruptly narrows. Rostrum thick, upper margins somewhat angled, 

 tip produced below in a slender spine, shorter in the old than in the 

 young; upper and lower surfaces a little concave; lower surface 

 triangular in shape, narrower than upper, and separated from it by 

 a deep lateral groove. (Fig. 53, c.) 



Body ^nd feet nearly smooth and naked. Chelipeds pubescent; 

 upper crest of hand laminiform, very prominent above insertion of 

 dactylus. Ambulatory legs slender, with no vestige of a thumb- 

 process on the penult article, excepting in the first pair, where there 

 is, at the distal fourth of the lower side, a small projection or socket 

 bearing a few hairs. 



Measurements. — Male, type, length of carapace 0.36 inch (9.1 

 mm.), width 0.27 inch (6.9 mm.). Male (47112), length 5.7, width 

 4 mm. Male (San Marcos), length 11, width 9 mm. 



Range. — Lower California, from Santa Maria Bay to Cape St. 

 Lucas and Gulf of California. 



Material examined. — Santa Maria Bay, Lower California; March 

 18, 1911; Albatross; 1 small male (47112), without chelipeds or legs. 



San Marcos Island; on kelp; June, 1921; Johnson and Baker, 

 California Academy Expedition; 2 males (Cal. Acad. Sci.). 



