1914] Dickerson: Fauna of the Martinez Eocene of California 119 



Cerithium Natica 



Turritella Gyrodes 



Architectonica Amaura (= Amauropsis) 



Calyptraea Fissurella 



Xenophora Enclimatoceras (= Hercoglossa) 



Pyrula is the equivalent of Ficopsis. Fulgur(f) dallianum Harris 

 is rather close to Perissolax blakei Conrad. They are generically the 

 same, at least. 



GENERA PRESENT IN MIDWAY BUT ABSENT IN MARTINEZ 

 The following genera listed by Harris have not been found in the 

 Martinez : 



Lithodomus Pyropsis 



Chama Leucozonia 



Gastrochaena Mazzalina 



Verticordia Levifusus 



Cadulus Levibucinum 



Atys . Murex 



Pleurotomella Calyptraphorus 



Drillia Aporrhais 



Caricella Mesalia 



Scaphella Eissoina 



Voluta Keilostoma 



Lyria Scala 



Mitra Solariella 



Exilia Pleurotomaria 



Of these missing genera the following are found in the Tejon, the 

 upper Eocene of the west coast: Cadulus (represented by Dentalium 

 pusillum Gabb), Drillia, Caricella, Voluta, Mitra, Exilia (represented 

 by Fusus dicker soni Weaver) Lyria, n. sp. 



PROPOSED CORRELATION 



The absence of several of the genera mentioned from the Martinez 

 such as Drillia, Caricella, Voluta, Mitra, Exilia, and Pseudoliva which 

 are typical Eocene forms over the world suggests that the Martinez 

 represents a stage in the Eocene of the United States which is at least 

 in part decidedly lower than the Midway. 



On account of the close relationship of the Martinez to the Chico- 

 Cretaceous, the much greater thickness of the Eocene strata on this 

 coast compared to that of the Gulf States, and the absence of certain 

 genera typical of upper, middle and lower Eocene, the writer con- 

 cludes that the Martinez is not only equivalent to a portion of the 

 Midway, but represents a still earlier stage of the Eocene as well. 



