CALIFORNIA STALK-EYED CRUSTACEA. 47 



Subtribe CYCLOMETOPA, or CANCROIDEA. 



Carapace generally broader than long, wide and regularly arcuated in 

 front, rarely quadrate or suborbicular in form; rostrum wanting. Epi- 

 stome short, transverse. Anteunules longitudinal or transverse. Palp of 

 the maxillipeds joined to the apex or inner angle of the merus. Branchiae 

 nine, the efferent branchial channels as in the Maioidea. Verges of the 

 male in the cox?e. 



Section CANCRINI Ortmann. 



Carapace rounded or widened, a dentate antero-lateral margin sharply 

 marked off frona a postero-lateral margin devoid of teeth. Front with 

 several teeth, one of which is median. Antennules longitudinal or 

 oblique. 



Genus Cancer L. 



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. Antennules longitudinal, or 

 nearly so. Basal autennal joint somewhat enlarged and united with the 

 front, 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.. 



Key to the Species. 



Carapace not undulated; size small C. gracilis. 



Carapace undulated, large species . 



Antero-lateral teeth distant, the posterior one the 



largest C. magister. 



Antero-lateral teeth contiguous. 



Front flattened and produced C. productus. 



Front not flattened nor produced C. antennarius. 



Cancer productus Randall. 



Cancer productus Eaxdall, Journ. Acad. Nat. Sci. Phila., Vol. VIII, 1839,. 

 p. 116. Dana, Crust. U. S. Expl. Expd., Part I, 1852, p. 156, PI. VII,. 

 fig. 3. Stimpson, Proc. Cal. Acad. Sci., Vol. I, 1856, p. 88; Journ. 

 Bost. Soc. Nat, Hist., Vol. VI, 1857, p. 461. Bate, in Lord's Nat. in 

 Vancouver's Island, Vol. II, 1866, p. 269. Lockington, Proc. Cal. 

 Acad. Sci , Vol. VII, 1877, p. 95. Smith, Rep. Prog. Geol. Sur. Can- 

 ada, 1879, B, p. 207. Rathbun R., The Fisheries of the U. S., Sec. 

 1, 1884, p. 771, PI. CCLXII. Ortmann, Zool. Jahrb. Abth. f. Syst., 

 Bd. VII, 1894, p. 425. Calman, Ann. N. Y. Acad. Sci., Vol. XI,,. 

 1898, p. 262. 



Platycarcinus productus Gibbes, Proc. Am. Ass. Adv. Sci., 1850, p. 177. 



Cancer perlatus Stimpson, Proc. Cal. Acad. Sci., Vol. I, 1856, p. 88. 



