52 



CALIFORNIA ACADEMY OF SCIENCES. 



Cancer gracilis Dana. 



Cancer gracilis Da'^a, Proc. Acad. Nat. Sci. Phila., Vol. VI, 1852, p. 73; 

 Crust. U. S. Expl. Expd., Vol. I, 1852, p. 153, Pi. VII, fig. 2. Stimp- 

 SON, Proc. Cal. Acad. Sci., Vol. I, 1856, p. 88; Journ. Bost. Soc. Nat. 

 Hist., Vol. VI, 1857, p. 460. Cooper, 1. c, 1860, p. 389. Locking- 

 TON, Proc. Cal. Acad. Sci., Vol. VII, 1877, p. 95. Newcombe, Bull. 

 Nat. Hist. Soc. Brit. Col., 1892, p. 23. 



Carapace quite strongly convex, finely granulated and not undulated. 

 Front not produced; the three median teeth reach further forward than 

 the outer pair; the central tooth is smaller than the others but projects 

 farther anteriorly. No tooth on the superior orbital margin. Postorbital 

 tooth larger than the ones behind it, which are low, triangular and sub- 

 equal in size. A small tooth on the nearly straight posterior margin. The 

 pointed extremity of the basal antennal joint does not extend nearly so far 

 forward as in the preceding species. A rounded lobe on the inferior 

 orbital margin just external to the basal antennal joint. Merus of the 

 malillipeds distally rounded. Merus of the chelipeds with the distal 

 extremity of the upper margin armed with two teeth as in magister; carpus 

 ridged on the outer surface as in magister and having a strong spine at the 

 antero-internal angle, and another spine below it; the upper edge of the 

 hand is acute and may bear a few teeth, but it is often edentulous; the 

 outer surface furnished with granulated costae, which sometimes become 

 quite faint. The fingers resemble those of magister; the upper margin of 

 the dactyl is acute but not dentate; legs long, nearly naked, the dactyls 

 slender, compressed. 



Sex. 



Leng 



th of Cai 



Male 





1.51 in. 

 1.60 in. 



(( 





1.70 in. 



Female 





1.90 in. 



( ( 





1.45 in. 



Breadth. 



Proportion 



2.30 in. 





1.52 



2.40 in. 





1.50 



2.55 in. 





1.50 



2.80 in. 





1.47 



2.13 in. 





: 1.47 



The males therefore appear to be relatively wider than the females. 



Vancouver Island (Newcombe), Paget Sound, Toma- 

 les Bay, San Francisco Bay! San Pedro! San Diego! 



This is one of the smallest species of the genus Cancer 

 and it is also the rarest of our species. It is more 

 closely allied to magister than to the other forms, but 



