1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 541 



Caecum californicum Dall. 



CcBcum Cooperi Cpr. Suppl. Rep. Br. As. 1864, p. 655, not 



CoBoum Cooperi Smith. Auu. Lye. Nat. Hist. N. Y., pp. 154, 168. 1862. 



8an Diego. Cooper. 



[The above synonymy shows that of the two species named G. Cooperi^ 

 that of Mr. Sanderson Smith has priority, and consequently the Cali- 

 foruiau species is the one which must take a new name instead of the 

 New York form. Through a failure to observe this Dr. Cooper fell into 

 the error of renaming G. Gooperi (New York) as G. iSmithii (Proc. Phil. 

 Acad. Nat. Sci. 1872, p. 154). D.] 

 Caecum orcutti Dall, n. s. 



[Shell small, stout, smooth, but not polished, light warm brown in 

 color and without sculpture, except very slight lines of growth. Shell 

 slightly curved, the anterior aperture very oblique, about at right 

 angles to the plane of the diameter of the plug, the superior margin 

 being the anterior ; plug glandiform, smooth, rounded without mucro ; 

 operculum brown, thin, smooth. Lou. of shell, 2.00; diameter 0.75™"". 



San -Diego, Orcutt, abundantly, under stones. 



This is the smallest and the only smooth Californian species of the 

 genus. D.] 

 Jeffrey sia translucens Cpr. 



One specimen, San Diego. 

 Barleeia subtenuis Cpr. 



Very abundant in the spring on sea-grass ; also var. rimata, Cpr. 



[Very frequently with a small Spirorbis growing on it larger than the 

 shell. D.] 

 Barleeia haliotiphila Cpr. 



,San Diego. Eare. 

 Bithinella binneyi Try on. 



Freshwater springs at Campo, San Diego County, California. 

 Bithinella intermedia Tryon. 



Freshwater springs on Cuyamaca Mountain, at a higher altitude than 

 the last. 

 Truncatella californica Pfr. 



Abundant. 

 Truncatella stimpsonii Stearns. 



Found this species in considerable numbers in company with Pedipes 

 unmilcatus, on and under smoothly-worn bowlders in caves on the ocean 

 beach north of False Bay, near high-water mark. 

 Fhasianella compta Gld. 



Thousands found in sea-grass on the inside of San Diego peninsula 

 in November, 1881. Usually incrusted with a small polyzoan {Defran- 

 cia intricata). 



[The operculum is white, prettily clouded with dark green. D.] 

 Bucosmia substriata Cpr. 



[Eare, San Diego, Dall. Oatalina Island, rare, Cooper.] 



