1894. PROCEEDINGS OF THE NATIONAL MUSEUM. 157 



Family M A o t r i d ^. 



MACTRA (STANDELLA) PLANULATA, C .> n r a <i . 



Specimens. Sau Juaiiico. Station 2828, 10 fatliomis off Lower Cali- 

 fornia; AlhatrosH. 



LABIOSA UNDULATA, Gould. 



^Baeta undulata, Gray. 



Valves only; rare. Loreto, Gabb. Occurs elsewhere in the Gulf and 

 up the coast northward to San Pedro. 



Family A n a t i n i d ^. 



THRACIA PL I C ATA, Deshayes. 

 ^ T. t.-uncata, Mighels. 



Very rare; valves only. La Paz (No. 73G02, TT. S. N. M.). 



PERIPLOMA PLANIirSGULA, S o w e r b y . 



-\- r, lenticularis, Sowerby. 



= P. argentaria, Conrad. 



= P. alta, C. B. Adams. 



= P. excurva + excurvaia, Carpenter. 



Numerous examples. 



San Juanico (No. 73518, U. S. N. M.); Loreto (No. 73517, U. S.N.M.), 

 Gabb. Common at many places on the ocean coast of the i)euinsula; 

 northward to Sau Pedro; common in the " fossil bank" at Spanish 

 Bight, Corouado peninsula, San Diego; perhaps northerly to Point 

 Concepcion. 



Family Core u l i d m, 

 CORBULA BICARINATA, Sowerby. 



Numerous specimens. 



Gulf of California (No. 73500, U. S. N. M.); Boca de los Piedras (No. 

 73641, U. S. N. M.); Mulege Bay (No. 73645, U. S. N. M.). 



Class SCAPHOPODA. 

 Family Dentaliid^. 

 DENTALIUM FISHERI, provisional uume. 

 One example. Los Animas Bay (No. 46204, U. S. N. M.). 



