22 CALIFORNIA ACADEMY OF SCIENCES. 



Epialtus productus Randall. 



Epialtus productus RANDALL, Jouru. Acad. Nat. Sci. Phila., Vol. VIII, 1839, 

 p. 110. GIBBES, Proc.Am. Ass. Adv. Sci., 1850, p. 173. DANA, Crust. 

 U. S. Expl. Expd., Part I, 1852, p. 133, PI. VI, fig. 2. STIMPSON, 

 Jouru. Bost. Soc. Nat. Hist., Vol. VI, 1857, p. 457. LOCKINGTON, 

 Proc. Cal. Acad. Sci., Vol. VII, 1877, p. 77. RATHBUN R., The Fish- 

 eries of the U. S., Sec. I, 1884, p. 778, PI. CCLXVIII. NEWCOMBE, 

 Bull. Nat. Hist. Soc. Brit. Col., 1893, p. 22. ORTMANN, Zool. Jahrb. 

 Abth. f. Syst., Bd. VII, 1894, p. 42. RATHBUN M., Proc. U.S.Nat. 

 Mus., Vol. XVII, 1894, p. 68. 



Carapace smooth and not distinctly areolated. Rostrum deeply notched, 

 the inner margins of the horns slightly concave, the outer convex. There 

 is a small, triangular preorbital tooth; postorbital tooth small. The mar- 

 gin between the postorbital and the large tooth at the antero-lateral angle 

 is concave and transverse. About midway between the antero-lateral 

 tooth and the posterior margin of the carapace there is a large tooth 

 pointing forwards and outwards; the sides of the carapace in front of the 

 posterior teeth are nearly parallel; the posterior margin has a strong con- 

 vexity in the middle. Chelipeds stouter, and except in old males, shorter 

 than the first ambulatory legs; carpus carinate on the outer side; hand 

 long and narrow, palm oblong, subcarinate above, becoming inflated with 

 age; fingers slender, bent downward and curved inward, the inner margins 

 dentate and contiguous throughout their length, except in old males in 

 which they may become more or less gaping at the base. Ambulatory 

 legs successively decreasing in length posteriorly, penultimate joints sub- 

 carinate, dactyls slender, spinulous below, and terminating in sharp, 

 slender claws. Abdomen of the female subelliptical, the last joint tri- 

 angular. 



Color reddish to olive brown mottled with small, round spots of a 

 darker hue. 



Length of ordinary specimen from tip of rostral horns 78 mm.; width 

 between antero-lateral horns 58 mm. 



Alaska to Lower California. 



This species is abundant on our coast; it is commonly 

 known as the "kelp crab " from the fact that it is 

 usually found on kelp the color of which it closely 

 resembles. There may be small, setose tubercles on the 

 median region of young specimens, but they disappear 

 with age, and there are two rows of curved setse on the 

 upper side of the rostrum which persist for a longer 



