128 CALIFORNIA ACADEMY OF SCIENCES. 



Cerritos, and is now in tlie United States National Museum. Found also in the- 

 Pleistocene of Twenty-sixth Street, San Diego. 



Pleistocene. — San Pedro; San Diego (Arnold). 



S u perf am ily CARD I T ACE A . 

 Family XIX. CARDITID.E. 



Genus Venericardia Lamarck. 



Shell suborbicular, inequilateral, radiately ribbed; hinge with two oblique cardinal teeth 

 and no laterals. 



Venericardia planicostata Lamarck is a characteristic species. 



54. Venericardia barbarensis Stearns. 



Venericardia barbarensis Stearns, Proc. U. S. Nat. Mus.,Vol. XIII, 1891, p. 214, PI. XVI, figs. 3, 4. 



Shell rounded, inequilateral, variable in outline, more or less oblique, moderately convex; 

 beaks small, slightly elevated and turned forward; surface ornamented with nineteen or twenty radi- 

 ating ribs, usually somewhat granulose; lunule small, slightly sunken, faintly defined; hinge-line 

 small, not thick ; hinge composed of, in left valve, a single strong cardinal sloping posteriorly 

 and a smaller tooth, often obscure, slanting anteriorly; a third tooth-like process is generally present, 

 situated under, and apparently a projection of, the edge of the lunule; the right valve has a single 

 strong cardinal tooth with a slanting, somewhat sinuous groove above and a slight notch and tooth- 

 like point below the upper part of the lunule; muscle impressions small. 



Dimensions. — Long. 19.5 mm.; alt. 17 mm.; diam. 14 mm. 



Distinguishable from V. ventricosa by more subrectangular outline, greater 

 relative length; greater number of ribs, less pfominent beak, much narrower and 

 longer hinge-line, and shorter, slighter posterior cardinal tooth, which is straight. 



ComiBon in Pliocene and lower San Pedro series of Deadman Island; rare 

 in Pliocene at Timm's Point and upper San Pedro series of Crawfish George's and 

 San Pedro. Found also west of bath-house at Santa Barbara. 



Living. — Santa Barbara Islands (276 fathoms) (Stearns). 



Pleistocene. — San Pedro (Arnold): Santa Barbara (Arnold). 



Pliocene. — San Pedro (Arnold). 



55. Venericardia ventricosa Gould. 



Cardiia venlricosa G\^\i., Proc. Bost. Soc. Nat. Hist., 1850, p. 276; Wilkes Expl. E.xped., Vol. XII, 



p. 417, PI. XXXVI, fig. 532, 1852, =C sublenla Con., =C nionilicosta Gabb, =C occi- 



dentalis Con., {fide Gabb, Pal. Cal., Vol. II, 1869, p. 100). 

 Venericardia borealis var. ventricosa Gld., Cpr., Brit. Assn. Rept., 1863, p. 643. Cooper, 7tli Ann. 



Rept. Cal. St. Min., 1888, p. 269. 

 Venericardia ve7ttricosa Gld., Stearns, Proc. U. S. Nat. Mus., Vol. XIII, 1S91, p. 216, PI. XVI, 



figs. 5 and (>. Williamson, Proc U. S. Nat. Mus., X'ol. XV, 1892, j). 190. 



