of the Pacific Shores of North America. 453 



thick villosity. Those of the first pair shorter than those of 

 the second, with fingers touching each other along the whole 

 length of their denticulated inner edges ; wrist somewhat 

 tuberculous above ; third article with four small distant 

 spines on the superior margin, the largest being at the sum- 

 mit of the abrupt expansion at the articulation of the fourth 

 article. A single subterminal spine on the third article of 

 the second pair of feet ; this spine becomes almost obsolete 

 in the posterior pairs, which are elsewhere smooth. Tarsi 

 short and thick, somewhat curved, with corneous tips easily- 

 separable in dry specimens. The color of exposed parts is 

 reddish inclining to roseate, becoming yellowish- white on 

 the sides. Fingers white. The following are the dimen- 

 sions of a female : — 



Length of carapax 5.55 inch. 



Width " " 4.54 " 



Length of rostrum from base of prseorbital spine . . 0.96 " 



Distance between rostral tips 0.39 " 



" " tips of prasorbital spines . . . 1 .30 " 



Length of 1st pair of feet . 4.90 " 



" " 2d " " 6.45 « 



"5th " " 4.75 " 



Taken on the coast of California, near San Francisco, by 

 Lieut. Trowbridge. 

 Mus. Smithsonian. 



LOXOKHYNCHUS CEISPATUS. Stimpson, n. s. 

 Plate XXII. f. 2, 3, and 4. 



Carapax very much elongated, somewhat triangular ; 

 regions separated by deep depressions. There are nine 

 large tubercles above, with sharp apices, between which 

 smaller ones are interspersed. These tubercles are as fol- 

 lows : one at the posterior summit of the stomachal region, 

 one at each hepatic region, (projecting laterally,) two on 

 each side at the branchial regions, and one at either extrem- 

 ity of the abruptly convex intestinal region. The sides of 



