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University of California Publications in Geology [Vol. 11 



tological work of these publications, done by Conrad, includes the 

 description of a number of new species from the Tertiary. These 

 descriptions are, for the most part, very meager and the illustrations 

 in many cases are so poor that some of the species will have to be 

 classed as indeterminate. Conrad 12 was one of the first to attempt 

 to correlate the invertebrate faunas of the Tertiary of the West Coast 

 with those in the East. He pointed out the similarity between certain 

 fossil species of the two regions. His correlation for all horizons 

 above the Eocene, however, was very general and only vaguely denned. 



J. D. Whitney, 13 the head of the first Geological Survey of Cali- 

 fornia, included what is now recognized as Eocene in the Cretaceous ; 

 everything above these horizons was referred either to the Miocene, 

 Pliocene or post-Pliocene or, as in many localities, the beds were de- 

 scribed as Tertiary. W. M. Gabb, who was the palaeontologist of 

 the Survey and whose excellent descriptions of Cretaceous and Ter- 

 tiary fossils have been of so much assistance to later geologists and 

 palaeontologists on the West Coast, described a few fossils from beds 

 in the Contra Costa Hills and in the region of Mount Diablo. 14 These 

 beds were designated as Miocene and Pliocene respectively, no attempt 

 being made to distinguish faunal zones. Of the species described, 

 some were listed as coming from the region near the town of Mar- 

 tinez ; a number of these came from the beds described and named 

 in this paper as the San Ramon formation, which is regarded as a 

 part of the San Lorenzo. 10 



It was more than thirty years after the time of Gabb's report 

 before any attempt was made to differentiate further the faunas of 

 the Tertiary of the West Coast. In 1892 a paper by W. H. Dall ia 

 and G. D. Harris appeared, entitled "The Neocene of North Amer- 

 ica. ' ' The portion of this paper which deals with the marine Neocene 

 formations of the West Coast is largely a compilation of previous 

 literature ; the most important exception to this is the description 

 of the Astoria beds in Oregon. A detailed discussion is given by 

 Dall of the lithology and of the occurrence of the fossils in these beds, 

 the name Astoria group being applied to a series of shales and Band- 

 it Conrad, T. A., Proe. Aead. Nat. Sei. Phila., vol. 7, p. 441, 1831 ; also, Paa 

 E.R. Reports, vol. 7, p. 189, 1857. 



is Whitney, J. D., Geol. Surv. Calif., Geol., vol. 1, pp. 1-498, 1860-1864. 



n Gabb, W. M., Palaeontology of California, vol. 2, pp. 1-63, 1869. 



I s Some of the Oligocene species described by Gabb from this general locality 

 are Antigona mathewsonii (Chione mathewsonii) , Dosinia mathewsonii, Dosinia 

 whitneyii (Chione wMtneyii), Mytilus mathewsonii, Spisula occidentalis (Hemi- 

 mactra occidentalis) , Agasoma gravidum, Ancilla fishii (Ancillaria fishvi), Molo- 

 pophorus biplicatus (Cuma biplicata) . 



16 Dall, W. H., and Harris, G. D., U. S. Geol. Surv., Bull. 84, pp. 1-349, 1892. 



