1921 J Schmitt: The Marine Decapod Crustacea of California 263 



at depths between 33 and 68 fathoms. The bottom in all three cases 

 was "very fine, green sand." The range of temperature (bottom) 

 9.3° to 9.8°C; range of salinity, 34.2 to 34.3. 



Pinnixa franciscana Rathbun 



Plate 42, figures 1, 2, 3, and 4 



Pinnixa franciscana Kathbun, Bull. U. S. Nat. Mus., 97, 161, text fig. 100, 

 pi. 35, figs. 1-4, 1918. 



Original Description of Female. — Near P. occidentalis, but carapace smoother, 

 cardiac ridge blunt and straight. Propodus of cheliped small, upper edge convex, 

 densely granulate, lower margin straight from near the wrist to end of finger; 

 outer surface with a granulate ridge just above lower edge, continued to end 

 of finger and fringed above with hair, also a line of granules through the 

 middle, and two lines of punctae and hairs on upper half. Fingers wide, not 

 gaping, tips crossing, a wide triangular tooth at middle of dactylus, a similar 

 tooth on distal half of fixed finger. First [ambulatory] leg reaches nearly to 

 middle of dactylus of second, second nearly to end of third, fourth to middle of 

 carpus of third; merus of third leg one and two-thirds times as long as wide, 

 distally narrow (Rathbun). 



Dimensions. — Type, female: length of carapace 5.7 mm.; width 11 mm.; length 

 of third leg about 12 mm. 



Type Locality. — San Francisco Bay, California, 10 to 12% fathoms ("Alba- 

 tross" station D 5709). 



Distribution. — San Francisco Bay, California (see below, Biological Survey 

 San Francisco Bay). 



Bemarks. — Male differs from female in sharpness of cardiac ridge. Cardiac 

 ridge in female may be somewhat sharp, as in female, station [D] 5743. The 

 merus of second [ambulatory] leg is very slender in the young female and increases 

 proportionally more rapidly in width than the body in size. Cheliped of male not 

 known (Rathbun). 



Biological Survey of San Francisco Bay. — Pinnixa franciscana 

 has been found only in San Francisco Bay, where it was taken at 

 seven of the dredging stations (D 5709, 5715, 5723, 5743, 5772, 5824, 

 5825), from off Point San Pedro in the upper bay to off the Mission 

 Rock in the lower bay, and ranging from I14 to 15^2 fathoms in 

 depth (see plate 9). One specimen was taken at all but one station 

 (D 5825), located about halfway between Angel Island and the 

 Southampton Shoal Light, where six were obtained. The bottom 

 in all cases, was more or less sandy mud accompanied in at least two 

 cases with numerous worm tubes, the probable habitat of this species. 

 The lowest and highest annual mean temperatures and salinities for 

 the stations at which P. franciscana was taken, given here in view of 

 its apparently sedentary habits, range respectively from 12.0° to 13.3° 

 C, and from 24.4 to 31.0. 



