142 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Sei. 



body of shales ends abruptly as though faulted and the water 

 plunges into a deep pool. 



The material in which the fossils occurs is very similar to 

 that of the main body of the shales, but the fossils here are 

 entirely confined to the disturbed and eroded area and not a 

 single fossil was found elsewhere in this exposure and none 

 at all was found in the main body of shale. 



The fossils are fragile and while abundant in this limited 

 locality are hard to separate from the shale. 



A mile west of this locality on the Horcones road a small 

 stream with high banks affords another exposure of the fos- 

 siliferous Alazan shales. These shales are evenly bedded and 

 have not been folded or broken as at the first locality. They are 

 immediately overlain by recent material so that relations were 

 not seen. The material here is a bluish shale which weathers 

 white, differing in appearance from the great body of shale to 

 the north which belongs to the Cretaceous and resembling very 

 closely beds found at Tlacolula Ranch, 18 to 20 miles west of 

 this locality on the Arroyo Puente. 



The fossils from the Alazan shales were submitted to Dr. R. 

 E. Dickerson, who reports that they are of Upper Eocene age, 

 containing some forms characteristic of the Tejon of California 

 and others of the Upper Eocene of the Gulf Coast. 



The following forms have been identified from these beds : 



Orbitoides, sp. 



Cristellaria, sp. 



Corbula, sp. 



Nucula (Acila), sp. 



Nucula monrcensis Aldrich 



Chione, sp. 



Pecten promens De Gregorio 



(Pseudamusium) calvatus Morton 

 - sp. 

 Tellina cf. subtriangularis Aldrich 

 Glycimeris, sp. 

 Mactra ?, sp. 

 Spisula, sp. 

 Dentalium, sp. 



stramineum Gabb 

 Cadulus subcoartatus Gabb 



