19 21 ] Schmitt: The Marine Decapod Crustacea of California 91 



below. Third maxillipeds with antepenultimate segment outwardly dilated, as in 

 C. alba. Hands slightly widened distally, shorter and broader than in C. alba, 

 the length being barely twice the width ; anterior margin more transverse than 

 longitudinal. Antennal scale shaped as in C. alba but much shorter, being only 

 a little over half as long as the carapace. 



Dimensions. — Type: length 55 mm.; length of carapace 15 mm., of antennal 

 scale 10 mm. The Bay specimens range up to 54 mm. in length, the largest taken 

 an ovigerous female ; the general average is between 34 and 47 mm. 



Type Locality. — Trinidad, Humboldt County, California. 



Distribution.— Chirikof Island, Alaska, to Santa Cruz, California, to a depth 

 of 26 fathoms. 



Biological Survey of San Francisco Bay. — Crago stylirostris is pri- 

 marily a bottom-dweller, living on a more or less hard, sand or sandy 

 bottom, occurring principally in that portion of the middle bay lying 

 west of Alcatraz, Angel Island, and the head of Raccoon Strait, 

 exclusive of Richardson Bay (see plate 7), as well as outside, where, 

 however, it was not found beyond the 26 fathom line.. Crago styli- 

 rostris was taken at only three hydrographic stations (H 4996 middle 

 bay; H 5005, 5015 lower bay, only one specimen at each). 



In the upper bay this species was taken at but 9% (2) of the 

 dredging stations at the extreme lower end between Points San Pedro 

 and San Pablo; in the middle bay at 38% (28) of the stations, of 

 which 75% (21) were in the western section denned above, inclusive 

 of Golden Gate; in the lower bay at only 5% (2) ; and outside at 

 47% (8) of the stations. Of the eleven eastern middle, upper, and 

 lower bay stations, only 9% (1) returned more than eleven speci- 

 mens and then only a total of thirty-three, while on the other hand 

 not less than 47% (17) of the thirty-six western middle bay and out- 

 side stations returned more than twelve, 22% (8) returned more than 

 thirty-three specimens. At five (62%) of these eight stations, fifty 

 and more specimens were obtained. 



With respect to the character of the bottom as stated above, we 

 find that thirty-one (77%) of the stations at which Crago stylirostris 

 was dredged had a more or less hard, predominantly sandy bottom, 

 of which eighteen (58%) were purely sand bottoms, while thirteen 

 (42%) contained a considerable admixture of gravel, rock, or stones; 

 six (15%) of the stations were made on a muddy sand or sandy mud 

 bottom; and only two (5%) on a purely mud bottom; the bottom at 

 one (2%) of the stations was not characterized. 



The extremes of temperature and salinity to which the distribution 

 of this species subjects it, ranged, respectively, from 8.7° to 16° C, 

 and from 17.5 to 34.1. 



