CLASS PELECYPODA 
185 
Psammobia californica Conrad, 1848. 
Plate 43, fig. 5. 
Publ. Puget Sound Biol. Sta., 4:5 7. 
Shell of medium size, elongated, nearly equilateral, beaks very minute, 
a little posterior to the middle, anterior end sub-truncate above and pro¬ 
duced and rounded below; posterior end evenly rounded. Surface smooth 
except for lines of growth. Length, 75; height, 45; diameter, 27 mm. 
(Oldroyd.) 
Conrad named and figured the species, but did not publish a descrip¬ 
tion. 
Type locality, California. 
Range. Aleutian Islands to San Diego, California. Also Japan and 
Kamchatka. 
Psammobia edentula Gabb, 1869. 
Plate 57, fig. 1. 
Pal. Cal., 2:53; pi. 15, fig. 11. 
Shell moderately large, thin, flattened, elongated sub-elliptical, nearly 
equilateral; beaks minute, a little posterior to the middle, projecting almost 
insensibly beyond the cardinal line; cardinal margin sloping slightly and 
perfectly straight toward the two ends; anterior end convexly and very 
obliquely sub-truncate above, produced and rounded below; posterior end 
broadly and regularly rounded, a little less prominent below than above 
the middle; basal margin nearly straight. Surface nearly smooth in the 
middle, marked by pretty distinct lines of growth toward the ends, espe¬ 
cially above. Length on beak to base, 1.3 inch; width, 2.6 inch; beak to 
anterior end, 1.45 inch. (Gabb.) 
Type locality, Pliocene of San Fernando, California. 
Range. San Pedro, Catalina Island, and San Diego, California, 
living. In the Pleistocene at San Pedro, and the Pliocene at San Fernando, 
California. 
Genus SANGUINOLARIA Lamarck, 1799. 
Shell large, sub-circular, inequivalve, more or less twisted, the right 
valve slightly flatter; the posterior cardinal in the left valve obsolete; the 
pallial sinus narrow in front and somewhat detached from the pallial line. 
Pal. San Pedro. (Arnold.) 
Type. Solen sanguinolentus Gmelin. 
Distribution. World-wide. 
Range in time. From the Eocene. 
Sanguinolaria nuttallii Conrad, 1837. 
Plate 55, figs. 1, 4. 
Jour. Acad. Nat. Sci. Phila., 7:230; pi. 17, fig. 6. 
Shell sub-ovate, thin, much compressed; posterior margin obliquely 
truncate; extremity angular; basal margin regularly arcuate; beaks small, 
