ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 345 



Superorder MALACOSTRACA.' 



Order DECAPODA. 



Suborder BRACHYURA. 



Subtribe CANCROIDEA. 



Section Cancrini. 



Genus Cancer Linne. 



Carapace transverse, subelliptical, indistinctly areolated; antero-lateral margins regularly 

 arcuated and armed with ten teeth; front narrow, cut into five teeth or lobes; eye-peduncles short, orbits 

 small, with two fissures in both upper and lower margins; antcnnules longitudinal, or nearly so; basal 

 antennal joint somewhat enlarged and united with the fi-ont, thus excluding the short flagellum from 

 the orbit; merus of the maxillipeds distally truncated, and not produced at the antero-external angle; 

 chelipeds subequal, the hand generally costate on the outer surface. 



407. Cancer breweri Gabb. 



Cancer breweri Gabb, Pal. Cal., Vol. II, p. i, PI. I, fig. i, 1869. Cooper, 7th Annual Rept. Cal. 

 St. Min., 1888, p. 227. 



" Hand shorter, more robust, and broader proportionally than that of C. magisler Dana; 

 upper margin flattened and bordered by two well-defined ridges, each bearing about four tubercles; 

 outer surface marked by five nearly obsolete ridges minutely tuberculated; fingers shorter than in 

 C. magister, the movable one more curved, and both with the denticles nearly obsolete" (Gabb). 



Ditnensions. — Length of hand 82 mm. 



The above description Is a copy of Gabb's original. A well preserved hand 

 from the lower San Pedro series of Deadraan Island corresponds almost exactly with 

 Gabb's figure of his type. G. macjister is the common large edible crab of the Cali- 

 fornia coast. 



Pleistocene. — San Pedro (Arnold). 



Pliocene. — Calleguas ranch, Ventura County (Brewer). 



1 Divisions of this suborder and generic description from "Synopsis of California Stalk-Eyed Crustacea.'* By S. J. Holmes. 

 Occasional Papers, Cal. Acad. Sci., No. VII, p. 47, 1900. 



( 44 ) May 29, 1903. 



