1914] Dickerson: Fauna of the Martinez Eocene of Calif ornia 99 

 FAUNA OF THE UPPER MARTINEZ (Continued) 



Loc. Loc. Loc. Loc. Loc. 



788 779 782 787 780 



Meretrix(f), sp .... .... x 



Ostrea weaver!, n. sp x ^ 



Ostrea, sp x 



Phacoides, sp x 



Psammobia cylindrica, n. sp X 



Pholadomya nasuta Gabb x .... x 



Paphia cf. clarki, n. sp .... .... x 



Solen stantoni Weaver x 



Tellina, sp., indet 



Dentalium cooperi Gabb x x 



Fusus cf. flexuosus Gabb x 



Natica, sp x 



Turritella pachecoensis Stanton x x 



Turritella infragranulata Gabb x x 



All of these localities are over 3200 feet above the base and may 

 therefore be regarded as representing the uppermost Martinez of this 

 region. Although they contain but one form, Solen stantoni, char- 

 acteristic of the upper horizon at the type locality of the Martinez 

 the absence of many of the species characteristic of the middle and 

 lower zones is noteworthy. While the evidence is meager, the strata 

 3200 feet or more above the base are tentatively correlated with the 

 uppermost zone of the type section. Localities 787 and 780 are 

 probably about two hundred feet below the base of the Tejon, so that 

 their faunas represent the very youngest Martinez in the whole 

 Lower Lake area. 



MARTINEZ OF SAN MATEO COUNTY 



A collection of fossils from a formation in the vicinity of San 

 Pedro Point was referred to the writer for determination and study 

 by Professor A. C. Lawson and Professor J. C. Merriam. The collec- 

 tion was made by Messrs. G. D. Gerson, R. W. Pack, and E. Behr 

 during the past four years. 



Professor A. C. Lawson, 25 in "A Sketch of the San Francisco 

 Peninsula, ' ' first described these beds as follows : 



(1) A basal formation of conglomerates, coarse grits, sandstones, shales, 



and argillaceous limestones, exposed in the vicinity of San Pedro Point 



The base of the series is exposed in the vicinity of San Pedro Point. Here the 

 basal detrital rocks mantle over the crest of the Montara granite ridge. A 

 little to the north of the ridge, on the slope to San Pedro Valley, the strata 

 are somewhat complexly folded. They have the appearance of having been 



25 Lawson, A. C., A Sketch of the San Francisco Peninsula, 15th Ann. Kept. 

 U. S. Geol. Surv., pp. 416, 436, 1894. 



