THE GKAPSOID CRABS OF AMEKICA. 



147 



exception is a female from San Francisco Bay, which has chelae 

 similar to those of the adult female but with the thumb somewhat 

 longer. 



Color. Can be told from P. faba by the constantly different color. 

 In formalin, the carapace and appendages of female have a light 

 greenish-yellow ground, with large blotches of coral red on anterior 

 half. Eggs orange-vermilion, sometimes chestnut. First 3 ambula- 

 tory legs with a rufous band which embraces the propodus and part 

 of the carpus. Male light dirty greenish- white, with bands on legs 

 like those of female. 



Fio. 90. PIXXIXA LITTOHALIS (31600). a, OUTER MAXILLIPED or FEMALE, X 



DOMEX OF MALE, X 5g. 



14 ; b, AB- 



A pair from near the station at Departure Bay are said by Doctor 

 Fraser to be yellow (in place of coral red), with a band of dull 

 salmon color on the legs. 



Measurements. Male (31600), length of carapace 7.4, width of 

 same 14 mm. Female (48427), length of carapace 16.3, width of same 

 26 mm. 



Habitat. Commensal in clams. Some were picked up on shore 

 (Holmes). Of 500 specimens taken by Fraser, the adults with few 

 exceptions inhabited the giant clam, Schizothaerus, while all the 

 young of both sexes were taken from the small clam, Mya. 



Range. From Sitka, Alaska, to San Diego, California. 



Material examined. 



Sitka, Alaska: W. H. Dall; 1 male, 1 female ovig. (17298). On 

 clam; L. A. Beardslee; 1 female ovig. (17956). 



