164 CALIFORNIA ACADEMY OF SCIENCES. 



the base of the rostmm, the posterior pair seen in Trowhridgii being 

 absent. Dorsal area about twice as long as its width across the middle. 

 Chelipeds much like those of Trowhridgii but there is no spijfxe at the 

 antero-internal angle of the carpus. Antero-lateral angles of the abdomi- 

 nal segments rounded; posterolateral angles subacute. 

 Length, 95 mm. 



Klamath Lake! Sikon Creek; Des Chutes River; 

 Walla Walla, Wenos Valley, Spokane Falls, Washing- 

 ton (Faxon); British Columbia in streams east of the 

 Cascades (Bate); Eel River, Humboldt County, Calif.! 



Astacus Gambelii (Girardj. 



Cambarus Gambelii Girard, Proc. Acad. Nat. Sci. Phila., 1852, p. 90;^ 



Ibid., 1853, p. 380. 

 Astacus Gambelii Agassiz, Proc. Acad. Nat. Sci. Phila., 1853, p. 375. 



Stimpson, Journ. Bost. Soc. Nat. Hist., Vol. VI, 1857, p. 492. Hagen, 



111. Cat. Mus. Comp. Zool. Harvard Coll., No. 3, 1870„ p. 90, Pis. I, 



III, and XI. LocKiNGTON, Ann. Nat. Hist. (5), Vol. II, 1878, p. 303. 



Faxon, Proc. Amer. Acad. Arts and Sci., Vol. XX, 1884, p. 152; Mem. 



Mus. Comp. Zool. Harvard Coll., Vol. X, No. 4, 1885, p. 136; Proc. 



U. S. Nat. Mus., Vol. VIII, 1886, p. 356; Ibid., Vol. XX, 1898, p. 666. 



Carapace obese, punctate. Rostrum short, acute, concave above, with 

 the sides serrated and converging to the tip; a small spine on either side 

 of the base behin-d which there may be a trace of a second pair. Dorsal 

 area over twice as long as the width across the middle. Chelipeds large; 

 merus much compressed, with the lower margins spinulous, the spine at 

 the antero-internal angle small or absent; a spine on the upper side near 

 the distal end; carpus devoid of spines, the upper edge with a longitud- 

 inal median depression; hands large, broad, scabrous, the upper surface 

 of the palm thickly pilose on either side of the middle; lower side of the 

 palm inflated. 



Ogden River, Utah; Idaho; Mouth of Yellowstone 

 River, Montana; Wyoming. 



This species has been reported from California, but 

 its occurrence there is not entirely certain. 



