100 CALIKOUNIA ACADl.MV OK SCIENCKS. 



occurs on the postt-rior m:ir^;in; surface' scul|)turt'd concentrically as in )'. coof>eri except that this 

 inciseil sculpture is not in harmony with the incremental lines; hinjje and teeth similar to }" cooperi. 

 Dimensions. — Long. 20.4 mm.; alt. 10 mm.; diam. 4 mm. ; from umbo to anterior end g mm. ; 

 to posterior end 12 mm. 



Tliis ilelicate little sliell rcsomMes )'. cooperi in many. re.spect.s, but i,s easily 

 (listiiij;iiisli;il)li' liy it^^ .■^mailer si/c, more dclicale slidl, the peeiiliar way in wliicli tlie 

 seuiptiire eiusscs the incremental line.s, and l)y it.s relatively hroader anterior end. 

 rrol)aldy the )'. <n)u/gilal(i Val. reported by Cooper (7th Ann. Kept. Cal. St. Min., 

 188S, p. 1270) as occurring at Deadman Island i^ )'. scinsurata hall. Spccinicns 

 identified by Dr. Dall. 



Three speciinen.s from lower San Pedro .series of Deadman island; rare. 

 Specimens of }'. scit^.turnta in the State Museum collection of fossils at Berkeley are 

 labeled ) . (imygdala. The specimen figured is from the lower San I'cdro series at 

 Deadman Island, and is now in the collection of Delos Arnold. 



Living. — Puget Sound (Carpenter). 

 Pleistocene. — San Pedro (Arnold. 



Superfamily ARCACEA. 



Family Vil. ARCID.E. 



Subfamily rECTUNCULlN^. 



Genus Glycymeris Da Costa. 



Shell orbicular, nearly equilateral, smooth or radiately striated; umbones central, divided by 

 a striated ligamental area; hinge with a semicircular row of transverse teeth; adductors subequal; 

 pallial line simple; margins crenated inside. 



Type, Area glycymeris Linn. 



19. Glycymeris barbarensis Conrad. • 



Plate XVIII, Fig. 9. 



Axinea barbarensis Co-a., Pac. R. R. Rept., Vol. VI, 1857, p. 71, PI. Ill, fig. 11; Vol. VII, 1S57, p. 



,94, PI. VI, fig. 3. 

 Axinea intermedia (not of Brod.; not of Carpenter, Brit. Assn. Rept., 1863, p. 644), of Cooper, 



in part, 7th Ann. Rept. Cal. St. Min., 1888, p. 230 (not of Keep, West Coast Shells, 1892, 



p. 169; not of Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192; not of Dall, 



Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 608. 



Shell of medium size, convex, thick, subcircular, with angular aspect at umbones caused by 

 the anterior dorsal margin being nearly straight; posterior end rounded; anterior end angular; sur- 

 face area between umbones and interior as in G. seplenirionalis. 



Dimensions. — Long. 33.3 mm.; alt. 32 mm.; diam. 22 mm. 



Distinguishable from G. septentrionalis by wider, more trigonal shell and angular 



