1914] Dickerson: Fauna of the Martinez Eocene of Calif ornia 119 



Architectonica 



Calyptraea 

 Xenophora 



Cerithium 

 Turritella 



Natica 

 Gyrodes 



Amaura (= Amauropsis) 

 Fissurella 



Enelimatoceras (= 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 



Gastroehaena 



Mazzalina 



Yerticordia 



Levifusus 



Cadulus 



Levibucinum 



Atys 



Murex 



Pleurotomella 



Calyptrapliorus 



Drillia 



Aporrhais 



Carieella 



Mesalia 



Seaphella 



Rissoina 



Yoluta 



Keilostoma 



Lyria 



Seala 



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, Carieella, Yoluta, Mitra, Exilia (represented 

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



The absence of several of the genera mentioned from the Martinez 

 such as Drillia, Carieella, Yoluta, 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. 



Proposed Correlation 



