21 



205 Rissoina interfossa Cpr 



[Todos Santos. D.] 



206 Isapis fenestrata Cpr 



Specimens from among oyster shells below low water, off an 

 old pile from San Diego bay. Also Todos Santos bay. Unalaska. 



207 Mesalia tenuisculpta Cpr 



San Diego. 



208 Bittium quadrifilatum Cpr 



San Diego. 



209 Bittium armillatum Cpr 



Abundant on sponges found during the spring on muddy flats, 

 San Diego bay, at low water; dead ones abundant among worn 

 shells. 



210 Cerithiopsis assimilata C B Adams 



San Diego. Not found alive. Monterey, Cal., to Panama. 



211 Caecum calif ornicum Dall 



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



Caecum Cooperi Smith, Ann. Lye. Nat. Hits. N. Y., pp. 154, 168. 

 1862. 



San Diego. Cooper. Monterey, Cal., to Baja Cal. 



[The above synonymy shows that of the two species named 

 C. Cooperi, that of Mr. Sanderson Smith has priority, and conse- 

 quently the Californian species is the one which must take the 

 new name instead of the New York form. Through a failure to 

 observe this Dr. Cooper fell into the error of renaming C. Cooperi 

 (New York) as C. Smithii (Proc. Phil, Acad. Nat. Sci. 1872, p. 

 154). D.] 



212 Caecum orcutti 



[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. Lon. 

 of shell. 2.00; diameter 0.75 mm. 



San Diego, Orcutt, abundantly, under stones. 



This is the smallest and only smooth Californian species of 

 the genus. Dall.] 



213 Jeffreysia translucens Cpr 



One specimen, San Diego. 



214 Barleeia haliotiphila Cpr 



San Diego. Rare. Monterey, Cal., to Baja Cal. 



215 Bithinella binneyi Tryon. 



Freshwater springs at Campo, San Diego County, California. 



216 Bithinella intermedia Tryon 



Freshwater springs on Cuyamaca Mountain, at a higher alti- 

 tude than the last. 



