98 University of California Publications in Geology ['VOL. 8 



Of these most are new species, the types of which in several cases 

 are the only ones thus far found. The ratio of Tejon forms in this 

 fauna is about 15 to 80 while that of the Meretrix dalli beds is 14 

 to 80. Most of the Tejon forms which range downward belong to the 

 same species in both cases. In other words, they are the persistent 

 forms. It is thus apparent that this fauna is nearly the equivalent 

 of the Meretrix dalli zone in the area north of Mount Diablo. Since 

 it is found five hundred to a thousand feet above the base of the 

 Martinez at Lower Lake, it is evident that we have strata at Lower 

 Lake which are considerably lower than any other Eocene known in 

 the state. The writer is inclined to believe that the fauna above listed 

 is slightly lower than that of the Meretrix dalli zone of the Mount 

 Diablo region. This impression is gathered in part from the aspect 

 of the new forms mentioned above and the possible occurrence of two 

 Tellinas which may occur in the Chico. The specimen listed as 

 Tellina cf. parilis Gabb seems to be identical with Gabb's description 

 and figure. The specimens of Tellina herndonensis, n. sp., agree with 

 one of Gabb's figures of T. hoffmaniana in volume I of the Palae- 

 ontology of California, but he unfortunately confused this species. 

 The figure in volume I does not agree with his figure for this species in 

 volume II. Rhynconella(f), sp., also lends a Cretaceous aspect to the 

 fauna. The absence of Pholadomya nasuta Gabb from the lower zone 

 and its presence in strata a thousand feet above is noteworthy. Of 

 all forms in the Martinez Pholadomya nasuta is one of the most widely 

 ranging, both stratigraphically and geographically, and we should 

 expect to find it in a Martinez fauna as well-preserved as this. 



The upper and middle portions of the Martinez at Lower Lake are 

 but sparingly fossiliferous. Schizaster lecontei Merriam, Turritella 

 pachecoensis Stanton, Ostrea weaveri, n.sp., which were found at 

 University of California Locality 782, are the only fossils which were 

 found in the middle of the Martinez section exposed at Lower Lake. 



The following species were obtained from the upper beds : 



FAUNA OP THE UPPER MARTINEZ 



Loc. Loc. Loc. Loc. Loc. 

 788 779 782 787 780 



Schizaster lecontei Merriam x 



Cucullaea mathewsonii Gabb x 



Leda gabbi Conrad x 



Leda alaeformis (Gabb) x 



Leda packardi, n. sp .... x 



Modiolus ornatus (Gabb) x 



