l<it; • CAMFOnNIA ACADKMY C>F S(;IKNC1«. 



Rare in the lower San Pedro series at San Pedro; common in I In- n|)pcr San 

 Pt'dro series at Los Cerritos, hut rarer in the same iiorizon at Diudnmn Islaiul and 

 San Pedro. Found also in tiie IMeistocene at Twenty-sixth Street, Sun Diego. 



Living. — Santa liarhara to San Diego (Cooper). 



Pleixtocene. — San Pedro (Cooper; Arnold): San Diego (Arnold). 



112. Semele pulchra Soirerby. 



Pl.ATK XV, FiCS. 1 AND Irt. 



Amphidesma pulchra Sby., Conch., Vol. Ill, No. 2, fig. 2. 



Semele pulchra Sbv., Carpenter, Brit. Assn. Rept., 1863, p. 640. Gaub, Pal. Cal., Vol. II, p. 94, 

 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 264. Keep, West Coast Shells, 

 p. 190, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 186. Dall, 

 Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, ji. 995. 



Shell small, oval, thin ; beaks turned forward; posterior sides shorter than the anterior, 

 slightly biangular; fold not very distinct; anterior dorsal marjjin slightly convex ; anterior end evenly 

 rounded ; surface sculptured with numerous fine, sliarp concentric ridges, and fine radiating 

 striations; interior as in S. decisa except more delicate, and cardinal tooth in each valve ])rominent. 



Dimensions . — Long. 22 mm.; alt. 1S.2 mm.; diam. 6 mm. 



Distinguisliahle from S. decisa hy .smaller, thinner .shell, finer concentric 

 sculpture and radiating striations. Specimens of the species in the State Museum 

 Collection at tlie University of California, P.erkeley, are labeled N. jlnrescens Old. 

 Specimens identified by Dr. Dall. 



Rather rare in the upper San Pedro series at San Pedro and Los Cerritos. 

 Found also in the Pleistocene at Twenty-sixth Street, San Diego. The specimen 

 figured is from the upper San Pedro series at San Pedro, and is now in the collection 

 of Delos Arnold. 



Living. — Santa Barbara to San Diego; Acapulco to South America (Cooper). 



Pleistocene. — San Pedro (Cooper; Ai-nold): San Diego (Cooper; Arnold). 



113. Semele pulchra Soverhy, montereyi, var. nov. 



Platk XV, Fics. 4 ANi> 4a. 



Shell small, oval, ventricose, thin; beaks quite posterior to middle of shell; anterior dorsal 

 margin long, nearly straight; anterior extremity evenly curved; posterior end much shorter than 

 anterior, evenly rounded; fold obsolete; cartilage-process deep, oblique; one prominent cardinal 

 tooth in each valve; lateral teeth distinct; pallial sinus very large, rounded, expanded interiorly. 



Dimensions. — Long. 23 mm.; alt. 17.5 mm.; diam. 11. 5 mm. 



Resembles S. jiulchra in size, but is much more oval, lacking the angular 

 appearance at the beak; the beaks are situated more anteriorly in var. montereyi and 

 the shell is much more ventricose. Easily differentiated from the typical S. pulchra. 

 Pronounced a new variety o( pulchra by Dr. Dall. 



Rare in lower San Pedro series at Deadman Island. 



