1917] Nomland: Fauna of the Santa Margarita Beds 295 



was given. The age of the beds corresponding to the " Jacalitos" was 

 regarded as uppermost Miocene. 



In 1908 Anderson 2 published another paper including a descrip- 

 tion of the same region. The term Coalinga Beds was then modified 

 so as to comprise a part of the "Jacalitos" and the Santa Margarita 

 above the lithologic member called the Big Blue. It was suggested 

 that the Coalinga Beds might be the equivalent of the San Pablo in 

 the northern part of the Mount Diablo Range. 



In the preliminary report on the Coalinga district by Ralph 

 Arnold and Robert Anderson 3 in 1908, the Coalinga Beds as defined 

 by F. M. Anderson were divided into Vaqueros, Santa Margarita, 

 and Jacalitos formations. The name Santa Margarita was used be- 

 cause of the similarity of the fossils to those occurring in that for- 

 mation in the San Luis quadrangle in San Luis Obispo County. 

 This formation was believed to be of upper middle Miocene age. The 

 Big Blue was tentatively included with the Santa Margarita. 



In a bulletin by Ralph Arnold 4 on the palaeontology of the 

 Coalinga district, a short list of species found in the Santa Mar- 

 garita was given. The formation was believed to be at least in part 

 older than the San Pablo. 



The latest report on the geology and oil resources of the Coalinga 

 district by Arnold and Anderson 5 does not differ essentially from 

 their earlier reports on this region. It includes a general discussion 

 of both the palaeontology and geology. 



In the study of the palaeontology of the San Pablo group, B. L. 

 Clark compared that fauna to the forms found in the Santa Mar- 

 garita. It was shown that nearly one-half of the species found in 

 the Santa Margarita also occur in the San Pablo. It was also stated 

 that this formation was the equivalent of only the upper part, the 

 Astrodapsis whitneyi zone, of the San Pablo. A historical summary 

 of the literature dealing with the San Pablo-Santa Margarita was 

 included. 



2 Anderson, F. M., A further study in the Diablo Bange of California, Proc. 

 Calif. Acad. Sci., ser. 4, vol. 3, 1908. 



s Arnold, Ealph, and Anderson, Eobert, Preliminary report on the Coalinga 

 Oil District, California, TJ. S. Geol. Surv., Bull. 357, 1908. 



* Arnold, Ealph, Palaeontology of the Coalinga district, Fresno and Kings 

 counties, California, U. S. Geol. Surv. Bull. 396, 1909. 



s Arnold, Ealph, and Anderson, Eobert, Geology and oil resources of the 

 Coalinga district, California, U. S. Geol. Surv. Bull.* 398, 1910. 



o Clark, B. L., Fauna of the San Pablo group of middle California, Univ. 

 Calif. Bull. Dept. Geol., vol. 8, no. 22, 1915. 



