180 CALIFORNIA ACADEMY OF SCIENCES. 



the enormous development of miocene strata in Southern 

 California. It is probable that this region from the pres- 

 ent shore line to the desert was not submerged during terti- 

 ary times; observations tending to confirm this view will be 

 recorded further on."^ 



CiiETACEOUs Strata. — The first evidence of the existence 

 of these in Lower California was furnished by a few fossils 

 sent to the national museum by Mr. C. B. Orcutt of San 

 Diego, who found them at the southern shore of Todos 

 Santos Bay. 



Dr. C. A. White has mentioned and described these fos- 

 sils, t arriving at the interesting conclusion that the beds in 

 which they occur belong to a formation which has hitherto 

 not been recognized, and which probably occu]3ies a posi- 

 tion between the Chico and Shasta groups. 



They are equivalent with another series previously found 

 by Dr. G. F. Becker^ along the shores of Mendocino County, 

 and consisting of sandstones and shales, resting unconform- 

 ably on metamorphic rocks, presumably to be referred to 

 the Shasta group. It has been proposed to call the new 

 series the Wallala group, from a locality near the northern 

 occurrence. The fauna described by Dr. White comprises 

 one new genus and five new species. Specially characteris- 

 tic of the formation is the new genus Coralliochama 

 (Chamidse), closely allied to the European genera of Caprima, 

 Plagioptychus and Ichthiiosarcolithes; further, a few small 

 species of Cerithium, Trochus and Nerita. Consulting the 

 sketch map of Todos Santos Bay (PI. IV), it may be seen 



; * Miocene fossils have recently been found at Boleo, opposite Guaymas, 

 ;n the southern part of the peninsula. They otcur in a series of gravels, 

 clay and marls, interstratified with audesitic volcanic material. See E. 

 Fuchs, Sur le gite de ouivre de Boleo. Bull. Soc. Geol. de France, XIV, 2, 

 79. 1886. 



t Bull. 22, U. S. G. S. On new Cretaceous fossils from California. Bull. 

 15, U. S. G. S. On the Mesozoic and Ceuozoic Palajo.ntology of California. 

 -" jBuU. No. 19, U. S. Geol. Survey. Notes on the stratigraphy of California. 



