PLATE XXXVIII. 
Pliocene Pelecypoda and Gasteropoda. 
(Unless otherwise stated all figures natural size.) 
Fig. 1. Area multicostata Sowerby. U.S.N.M. 12574. Right valve; longitude 101 
mm. Recent, San Diego. Found in the lower Pliocene (Fernando 
formation) in the Puente Hills, Orange County, and in the vicinity of 
Los Angeles. 
Fig. 2. Cardium quadrigenarium Conrad var . fernandoensis Arnold. U.S.N.M. 164947. 
Type. Imperfect left valve; longitude 58 mm. Lower Pliocene (Fer¬ 
nando formation), Elsmere Canyon, near Newhall, Los Angeles County. 
A common variety in the lower Pliocene. The typical form with 44 
ribs and less obliquity is found in the Recent. 
Fig. 2a. Same specimen as fig. 2. View of umbos from above. 
Fig. 3. Area trilineata Conrad. U.S.N.M. 164948. Right valve of medium-sized 
specimen; longitude 40 mm. Same locality as fig. 2. A common species 
in the Pliocene of California. Also appears to extend down as far as the 
middle Miocene (Monterey). 
Fig. 3a. Same specimen as fig. 3. Umbos and hinge area viewed from above. 
Fig. 4. Area trilineata Conrad. Portion of an adult left valve, showing the more com¬ 
plex sculpture of the ribs in the later stages of growth; altitude 60 mm. 
Same locality as fig. 2. 
Fig. 5. Leda taphria Dali. U.S.N.M. 164952. 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. 
Fig. 5 a. Same specimen as fig. 5. View of umbos from above. 
Fig. 6. Neverita recluziana Petit. U.S.N.M. 164960. Back view; latitude 25 mm. 
Same locality as fig. 2. A common species from the Pliocene to the 
Recent fauna; alsQ probably occurs in the Miocene. 
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