1916J 



Dickerson : 



Tejon Eocene of California 



379 



List of Species From Localities in the Balanophyllia Variabilis Zone, 

 South of Mount Diablo — (Continued) 



469 477 714 720 725 729 730 



Neverita secta Gabb x 



Nassa antiquata Gabb x 



Nassa cretacea Gabb x 



Nyctilochus hornii (Gabb) x 



Olivella mathewsonii Gabb x 



Pseudoliva lineata Gabb x 



Perissolax blakei (Conrad) x 



Turritella andersoni, n. sp x .... 



Turritella uvasana Conrad x .... x 



Turritella buwaldana, n. sp x x 



The species formerly identified in collections made from this 

 locality and from the Marysville Buttes as Trochocyathus striatus 

 Gabb proves to belong to the genus Balanophyllia according to Mr. 

 John Nomland, who has made a very careful study of West Coast 

 fossil corals. The species found south of Mount Diablo, which has 

 been described by him under the name of Balanophyllia variabilis, 

 appears to be larger, longer and more uniformly horn-shaped than 

 the form, from the Marysville Buttes, which as a rule suddenly en- 

 larges in the upper two-thirds of the corallum. The cross-sections 

 of the two corals appear to be identical. The differences cited may 

 be varietal at least. The true Trochocyathus striatus appears to 

 range through both the Rimella simplex zone and the Balanophyl- 

 lia variabilis zone, while Balanophyllia variabilis ranges through the 

 two upper zones and does not appear in the Rimella simplex zone. 

 The absence of several species characteristic of both the Siphonalia 

 sutterensis zone above and the Rimella simplex zone below are the 

 principal characteristics of this fauna. In other words, this zone 

 is transitional between the second and the uppermost zone of the 

 Tejon group. 



Taken as a whole, the 2600 feet of the Tejon south of Mount 

 Diablo may be divided into three main divisions, the lowermost, the 

 middle consisting of the three bluffs and their intervening strata, 

 and the upper. Within these are recognized several faunal zones : 

 (1) Turbinolia zone; (2) Rimella simplex zone; (3) Balanophyllia 

 variabilis zone. 



Tejon Localities of 1911 Summer School 

 All localities in the following list are in the Tejon group, Mount 

 Diablo Quadrangle, Contra Costa County, California. 



