/ YOL.XY;] «PROCEEDINGS OF THE NATIONAL MUSEUM. 205 
Family TURRITELLID. 
Genus TURRITELLA Lam. 
Turritella Cooperi Cpr. 
Dead shells are not uncommon; living ones very rare. 
Turritella (Mesalia) lacteola Cpr. 
Three found. (C. T.S.) 
Family CERITHIITD®. 
Genus CBRITHIDEA Swainson. 
Cerithidea californica Held. (1840 +- C. sacrata, Gld. 1849, + C. pullata Gld.). 
Plentiful on mud flats. ‘Several variations are caused by the 
amount of freshness in the water; sometimes marked by yellow bands.” 
(J. G. ©.) 
Genus BITTIUM Leach. 
Bittium asperum Cpr. 
Dead Man’s Island. Fossil in San Pedro City. (J. G. C.) 
Bittium quadrifilatum Cpr. Pl. xx1, fig. 4 
A few found living. 
Family LITTORINID. 
Genus LITTORINA Fer. 
Littorina planaxis Nutt. 
Abundant on rocks. 
Littorina scutulata Gld. 
Less abundant than the former. 
Littorina scutulata var. plena Gld. 
A few with the type. 
Littorina scutulata var. 
Six or eight. This variety is small and almost black. 
Genus ASSIMINBA Leach. 
Assiminea californica Cooper. 
One living and one dead example at San Pedro. (C. T. 8.) 
Genus LACUNA Turton. 
Lacuna unifasciata Cpr. 
Three dead. 
Lacuna solidula Lovén. 
Rare living; San Pedro. (C. T. 8.) 
