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EXPLANATION OF PLATE 18 



Fauna of Martinez Eocene 



"Fig. 1. Aturia mathewsonU Gabb. X 1. 



This eephalopod occurs both in Martinez and Te.jon. 



Fig. 2a. Nautilus stephensoni, n. sp., side view. X 1. 



Fig. '2b. Nautilus stephensoni, n. sp., back view. X 1. 



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