CALIFORNIA STALK-EYED CRUSTACEA. 165 



Astacus Trowbridgii St. 



Astacus Trowbridgii STIMPSON, Proc. Bost. Soc. Nat. Hist., Vol. VI, 1857, 

 p. 87; Jouru. Bost. Soc. Nat. Hist., Vol. VI, 1857, p. 493. COOPER, 

 Kept. Expl. and Sur. Pacific Ocean, Vol. XII, Book 2, 1860, p. 388. 

 HAGEN, 111. Cat. Mas. Comp. Zool. Harvard Coll., No. 3, 1870, p. 93, 

 PI. Ill, fig. 171, and PI. X. FAXOX, Proc. Amer. Acad. Arts and Sci., 

 Vol. XX, 1884, p. 152; Mem. Mus. Comp. Zool. Harvard Coll., Vol. 

 X, No. 4, 1885, p. 134; Proc. U. S. Nat. Mus., Vol. VIII, 1885. p. 356. 

 Ibid., Vol. XX, 1898, p. 666. 



Carapace obese, punctate, nearly smooth, but roughened by minute 

 prominences at the sides, and furnished with two pairs of spines at the 

 base of the rostrum. Kostrum long, concave above, the sides very slightly 

 converging anteriorly, each ending in an acute, upturned spine separated 

 by a rounded notch from the long, slender, acuminate median spine which 

 is also somewhat upturned. Antennules with a small spine on the lower 

 side of the basal joint near the tip; peduncle shorter than the rostrum. 

 Antennae shorter than the body, with a strong spine on the outer side of 

 the outer basal joint; acicie acuminate, nearly equaling the rostrum. 

 Epistome triangular. Chelipeds long, but shorter than the body; merus 

 compressed and armed below with a double series of spines, the outer 

 series containing the less number; a strong spine at the infero-distal 

 angle; a spine at the anterior end of the outer surface and another on the 

 upper surface a little behind the anterior end; a spine at the antero-internal 

 angle of the carpus and another on the anterior margin of the lower side; 

 hands large, rough and punctate, with minute setae in the punctures; fin- 

 gers narrow, longer than the palm, irregularly dentated within, and spinu- 

 lous toward the distal end of the outer margins; inner margin of the dactyl 

 convex, the outer slightly concave. The lateral wings of the abdominal 

 segments have the antero-distal angles rounded and the postero-distal 

 angles subacute. Telson longer than broad, the terminal division nearly 

 semicircular. Cardiac area wide. 



Length of body, 141 mm.; of cheliped, 106 mm.; of hand, 54 mm. 



Columbia River, Oregon! Streams emptying into 

 Shoalwater Bay (Cooper); Monterey (Faxon). The speci- 

 men from the latter locality was a large female " said to 

 have been taken from a bunch of seaweed in salt water." 



