22 BULLETIN 112, UNITED STATES NATIONAL MUSEUM. 



MODIOLUS RECTUS Conrad, 1837. 



Journ. Acad. Nat. Sci. Phila., vol. 7, p. 243, pi. 19, fig. 1. 

 Bolimis Bay, California, to Magdalena Bay, Lower California. 



MODIOLUS FLABELLATUS Gould. 1850. 



Boston Journ. Nat. Hist., vol. 3, p. 343; Rep. U. S. Expl. Exp. Moll., p. 453, 



fig. 5G1. 

 Vancouver Island to San Diego, California. 



MODIOLUS CAPAX Conrad, 1837. 



Journ. Acad. Nat. Sci. Phila., vol. 7, p. 242; Conch. Icon. Modiola, pi. 3, 



fig. 11. 

 Santa Barbara, California, to Payta, Peru. 



MODIOLUS FORNICATUS Carpenter, 1864. 



Suppl. Kep. Brit. Assoc., p. 643; Ann. Mag. Nat. Hist, ser. 3, vol. 15, p. 178. 

 Trinidad to San Pedro and Cortez Bank, California. 



MODIOLUS (POLITUS VerriU, 1880, var.?) PALLIDULUS Dall, 1916. 

 .Proc. U. S. Nat. Mus., vol. 52, p. 404. 



Off Bodega Head, California, and south to Cerros Island, Lower California, 

 in deep water. 



Subgenus Gregariella Monterosato, 1883. 



GREGARIELLA OPIFEX Say, 1825. 



Journ. Acad. Nat. Sci. Phila., vol. 4, p. 3G9. pi. 19, fig. 2. 

 Santa Barbara, California, to Gulf of California. 



Subgenus Brachydontes Swainson, 1840. 



BRACHYDONTES DEMISSUS Dillwyn, 1817. 



Descr. Cat. Rec. Shells, vol, 1, p. 314 ; Journ. Acad. Nat. Sci. Phila., vol. 7, 



pi. 20, fig. 7. 

 Imported with " seed " oysters from the Atlantic coast. San Francisco 



Bay, on oyster beds. 



Genus BOTULA Morch, 1853. 



Subgenus Adula H. and A. Adams, 1857. 



ADULA DIEGENSIS Dall, 1911. (Plate 1, figs. 1, 3.) 



Nautilus, vol. 24, No. 10, p. 110 ; vol. 30, No. 1, p. 2. 

 San Francisco Bay to Cape San Lucas. 



ADULA FALCATA Gould, 1851. 



Proc. Boston Soc. Nat. Hist., vol. 4, p. 92; Mex. and Cal. Shells, pi. 6, 



fig. 9. 

 Coos Bay, Oregon, to San Diego, California. 



ADULA CALIFORNIENSIS Philippi, 1847. 



Zeitschr. Mai., p. 113; Conch. Cab., ed. 2, Lithopharja, pi. 5, fig. 19. 

 Vancouver Island to San Diego, California. North Japan. 



Genus DACRYDIUM Torell, 1859. 



DACRYDIUM PACIFICUM Dall. 1916. 



Proc. U. S. Nat. Mus., vol. 52, No. 2183, p. 405. 

 Bering Sea, 1401 fathoms. 



