544 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxii. 



Plate XLVIII. 



Fig. 1. Arcavndticodata^o-wevhY- Cat. No. 12574, U.S.N. M. Rij^ht valve; longitude 

 101 mm. Recent, San Uiego. Found in the lower Pliocene (Fernando 

 formation) in the Puente Hills, Orange County, and in the vicinity of Los 

 Angeles*. 



2. Cardium quadrigenarium Conrad, var. fenwvdoetisis, new variety. Cat. No. 



164947, U.S.N.M. Holotype. Imijerfect left valve; longitude 58 mm. 

 Lower Pliocene (Fernando formation), Elsmere Canyon, near Newhall, 

 Los Angeles County. A common variety in the lower Pliocene. The typ- 

 ical form with 44 ribs and less obliquity is found in the Recent. 

 2a. View of umbos of same specimen from above. 



3. Area trilineata Conrad. Cat. No. 164948, U.S.N.M. Righfvalve of medium- 



sized specimen; longitude 40 mm. Same locahty as fig. 2. A common 

 species in the Pliocene of California. Also appears to extend down as far 

 as the middle Miocene (Monterey). 

 3a. Umbos and hinge area of same specimen viewed from above. 



4. ^rm ^ri/mmto Conrad. Cat. No. 164948, U.S.N.M. Portion of an adult left 



valve, showing the more comi^iex sculpture of the ribs in the later stages 

 of growth; altitude 60 mm. Same locality as fig. 2. 



5. Leda taphria Call. Cat. No. 164952, U.S.N.M. Right valve; longitude 36 



mm. ; twice natural size. Same locality as fig. 2. This species is common 

 from the Pliocene to the Recent fauna in the California province. 

 5a. View of umbos of same specimen from above. 



6. Neverita reduziana Feiit. Cat. No. 164960, U.S.N.M. Back view; latitude 25 



mm. Same locality as fig. 2. A common species from the Pliocene to the 

 Recent fauna; also probably occurs in the Miocene. 



Plate XLIX. 



Fig. 1. O.^trea veatchli Gahh. Cat. No. 153827, U.S.N.M. Exterior of valve; altitude 

 90 mm. Lower Pliocene, San Diego. An abundant and characteristic 

 species in many of the Pliocene localities from southern California to Cerros 

 Island, off Lower California. 



2. CalUsta {Amiantis) callosa Conrad. Cat. No. 164953, U.S.N.M. Imperfect left 



valve; altitude 50 mm. Lower Pliocene (Fernando formation), Elsmere 

 Canyon, near Newhall, Los Angeles Count}^ Base evenly rounded in per- 

 fect specimens. Common from Pliocene to Recent. 



3. CalUsta snhdiaphana Carpenter. Cat. No. 164951, U.S.N.M. Imperfect right 



valve; longitude 41 mm. Same locality as fig. 2. Abundant in the Plio- 

 cene and also found in the Recent. 



4. Tcrebratalia smithi Arnold. Cat. No. 164977, U.S.N.M. Pedicle valve; longi- 



tude 42 mm. Pliocene, Temescal Canyon, 3 miles north of Santa Monica, 

 Los Angeles County. Known only from the Pliocene. A somewhat vari- 

 able species. 

 4«. View of brachial valve of same specimen. 



5. Terebratalia smithi Arnold. Cat. No. 164977, U.S.N.M. Pedicle valve; longi- 



tude 29 mm. Same locality as fig. 4. More prominent ribbing than speci- 

 men shown in fig. 4. 

 5a. View of brachial valve of same specimen. 



6. Terebrataliaoccidentalis DaU. Cat. No. 164996, U.S.N.M. Brachial valve; lon- 



gitude 40 mm. Same locality as fig. 4. This species is most variable, as is 

 evidenced by this and the following figures, which show a series collected 

 at one locality. Found in the lower Pliocene (and possibly upper Miocene). 



