1921 1 Schmitt: The Marine Decapod Crustacea of California 233 



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

 anteriorly. Merus of outer maxillipeds elongated, rounded anteriorly. Carpus of 

 chelipeds with two spines, one above, at distal angle, and a second below this, on 

 inner angle; fingers of chelipeds without dark color. Dactyls of ambulatory legs 

 slender, not flattened. 



Dimensions. — Type: length of carapace 27.3 mm., greatest width 40.2 mm. 

 Specimens collected in San Francisco Bay ranged from 3 to 76 mm. in width of 

 carapace. 



Color. — In life color is olive overlaid with minute reddish brown spots, which 

 are more numerous on the teeth of the anterolateral margin and on the front, 

 giving to the whole a brownish tinge; edges of teeth, under parts, and greater 

 portion of legs, yellowish. There is little variation in color among individuals 

 and small difference between fresh and alcoholic specimens (Weymouth). 



Type Locality. — San Francisco, California. 



Distribution. — Kasaan Bay, Prince of Wales Island, Alaska, to Playa Maria 

 Bay, Lower California. Shallow water to 56 fathoms (Bathbun). 



Biological Survey of San Francisco Bay. — Cancer gracilis (see 

 pi. 6) ranges from a little north of Point San Pedro, in the upper bay 

 (D 5716), well clown toward the lower end of the lower bay (D 

 5847), and outside to the San Francisco bar (D 5733) and the fishing 

 grounds (D 5785, and by the commercial trawlers in July, 1912). 

 In all it was taken at fourteen dredging stations and at two shore 

 stations : Sausalito, along shore and in the seine, and Point Bonita, 

 between tide marks. Of the dredging stations only one (D 5716) 

 occurs in the upper bay, eight (D 5702, 5742, 5797-5799, 5826, 

 5828) in the middle bay, three (D 5802, 5847, 5849) in the lower 

 bay, and two (D 5733, 5785) outside. Cancer gracilis occurs more 

 abundantly at stations of 12 fathoms and less in depth. Of such 

 there are ten at which the average number of specimens taken was 

 two and seven-tenths. Of the other four dredging stations at which 

 this species was taken, one is intermediate, 10 to 16 fathoms, with one 

 specimen, and three exceed 13 fathoms (D 5702, 13 to 17 fathoms; 

 D 5742, 20 to 30 fathoms; D 5785, 39 to 40 fathoms), with an average 

 of one and three-tenths specimens taken at each. 



There also appears to be a fairly close correspondence between 

 depth and number of specimens per haul, and the character of the 

 bottom. All of the stations of 12 fathoms or less Avithin the bay 

 were made on a predominantly muddy bottom, running from the 

 upper bay through the eastern part of the middle bay, behind Angel 

 Island, down into the lower bay. The station of intermediate depth 

 designated above should be included in this series with respect to 

 character of bottom. The outside station of less than 12 fathoms had 

 a bottom of "fine, very clean, gray sand," and returned only a single 



