PLATE XXV. 
Eocene Pelecypoda. 
(All figures natural size.) 
Fig. 1. Venericardia planicosta Lamarck. U.S.N.M. 1G4973. Left valve; longitude 
84 mm. Eocene, Little Falls, Wash. This is the most widespread and 
characteristic Eocene species in the world. Found in the Sespe and 
Silver Thread districts, Ventura County. 
Fig. la. Same specimen as fig. 1. View of anterior end of both valves. 
Fig. 16. Same specimen as fig. 1. View of both valves from above. 
Fig. 2. Cardium cooperii Gabb. LLS.N.M. 164998. A decorticated right valve; longi¬ 
tude 35 mm. Eocene, Rose Canyon, San Diego County. A common 
species in the Eocene of the west coast. 
Fig. 2a. Same specimen as fig. 2. View of both valves from above. 
Fig. 3. Mcretrix hornii Gabb. Left valve; longitude 36 mm. Pal. Cal., vol. 2, pi. 30, 
fig. 78. A common species in the Eocene of the west coast. 
Fig. 4. Modiolus ornatus Gabb. Right valve; longitude 38 mm. Pal. Cal., vol. 1, 
pi. 24, fig. 166. Another species found in most Eocene faunas of the 
west coast. 
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