1921] Schmitt: The Marine Decapod Crustacea of California' 89 



Crago alba (Holmes) 



Crangon alba Holmes, Oceas. Papers Calif. Acad. Sci., 7, 174, 1900; 

 Kathbun, H. A. E., 10, 117, figs. 56, 57, 190-4; Hilton, Jour. Ent. Zool., 

 Pomona Coll., 10, 54, 1918. 



Pig. 59. Crago alba, J ; a, acicle, X 2 ; b, dorsal view of orbital region of cara- 

 pace, X 4; c, chela, X 2% (from Eathbun, U. S. N. M.). 



Characters. — Sixth segment of abdomen rounded beneath, not grooved. Third 

 maxillipeds reaching the end of the blade; antepenultimate segment much 

 expanded. Hands very stout, only two and one-fourth times as long as the width 

 measured from the inner base of the immovable spine; the anterior margin is more 

 longitudinal than transverse. Antennal scale about three-fourths the length of 

 the carapace; blade with very oblique inner margin, the tip scarcely wider than 

 the adjacent portion of the spine ; spine extending considerably beyond the blade. 



Dimensions. — The specimens taken in connection with the Survey ranged from 

 32 to 45 mm. in length, the average being about 36 mm. in length, from tip of 

 rostrum to end of telson. 



Color. — Nearly white (Holmes). White dotted with black (Hilton). 



Type Locality. — Monterey Bay, California. 



Distribution. — From Vancouver Island, British Columbia, to San Diego, Cali- 

 fornia, to a depth of 47 fathoms (Eathbun). 



Biological Survey of San Francisco Bay. — Crago alba was dredged 

 only once in the course of the survey, eight specimens at D 5790, 

 outside, in 33 to 35 fathoms ; bottom very coarse, variegated sand, 

 with a small proportion of fine sand; temperature 9.7° to 11.5° C; 

 salinity 33.9. Over fifty specimens of Crago alaskensis elongata were 

 also taken at this station. 



