1921] Schmitt: The Marine Decapod Crustacea of California 93 



broad and slightly rounded at extremity, spine exceeding blade. Fifth segment 

 of abdomen not carinate. 



Dimensions. — Type: about 76.2 mm. The Bay specimens ranged up to 82 mm. 

 in length from tip of rostrum to end of telson for the largest female; the average 

 for the greater number of specimens taken is between 47 and 62 mm. 



Color. — Dark and light yellowish gray mottled. Eyes salmon-colored in life 

 (Stimpson). 



Type Locality. — San Francisco Bay, California. 



Distribution. — Southeastern Alaska to San Diego, California, to a depth of 

 29 fathoms. 



Biological Survey of San Francisco Bay. — Crago franciscorum is 

 universally distributed throughout the bay, extending well up into 

 Suisun Bay, from which it is the only decapod recorded, down into 

 the lower bay as far as suitable collecting apparatus was employed 

 (D 5847, south of which only oyster tongs were used), and outside 

 to the fourteen fathom line. 



It was taken in the upper bay at twenty (91%) of the dredging 

 and thirty-five (44%) of the hydrographic stations; in the middle 

 bay at fifty-one (70%) of the dredging and thirty- three (30%) of 

 the hydrographic stations; in the lower bay at fifteen (39%) of the 

 dredging and sixty-nine (64%) of the hydrographic stations; and 

 outside at eight (47%) of the dredging stations, only. 



Although taken at seven less dredging stations than Crago 

 nigricauda, as compared with that species Crago franciscorum is 

 preponderantly an inhabitant of the upper water layers, being an 

 abundant and oft recurring catch of the tow-net. It was taken, in 

 all, at one hundred and thirty-seven (45%) of the total number of 

 hydrographic stations, of which eighty-six (63%) returned more 

 than ten specimens each. 



As Stimpson remarked, this species "is found very abundantly in 

 sandy coves around the Bay." We found it even more abundant in 

 the more or less muddy regions of the bay, principally in the upper, 

 lower, and the eastern and upper portions of the middle bay as can 

 readily be seen in a review of the tow-net hauls. These were all made 

 with the same gear, at approximately the same depth and are therefore 

 fairly comparable. From these hydrographic (tow-net) stations, fifty 

 or more specimens were taken at fourteen (40%) of the upper bay 

 stations; at nineteen (28%) of the lower bay stations; and at only 

 six (18%) of the middle bay stations, all of which were in the upper 

 and eastern portions, lying east of Alcatraz, and east and north of 

 Angel Island. No specimens were taken in the tow-net outside. 



