Crandall — Santa Clara Valley Region in California. 41 



Horsetown are entirely conformable in dip with those of the 

 Knoxville, indicating continuous deposition as proven by Diller 

 and Stanton through the Shasta-Ohico series in northern Cali- 

 fornia. The upper part of this four thousand feet may be con- 

 sidered Chico, on the evidence of the Chico fauna. Northwest 

 of Jordan's ranch, down Arroyo del Yalle, the Chico is over- 

 lain by massive, light yellow, cavernous weathering sandstones, 

 conformable in dip. No fossils were found, but the beds re- 

 semble the Eocene as found in other places in middle California, 

 and are similar to the series described by Mr. Turner as over- 

 lying the Chico at Mt. Diablo. At the latter place they have 

 been identified by the presence of Turritella uvasana and other 

 characteristic Eocene fossils. 



Milpitas. — The Milpitas locality is southw r est of and is prac- 

 tically a continuation of the Pleasanton region. The fauna is 

 typically Knoxville in character. 



Ancella Pioclii Gabb 

 Uoplites (fragment) 

 .Belernnites (fragment) 

 Pecten complexicosta Gabb 



The exact locality from which these fossils come is on the w r est 

 side of the range separating Santa Clara and Calaveras valleys, 

 and is about 2|- miles northeast of Milp'itas. Aucellae were 

 found in several other localities southeast of this place along 

 the foot of the Monument Peak ridge. The locality, at which 

 fossils are most plentiful, is on the road from Milpitas to Cala- 

 veras Valley, about a quarter of a mile east up the grade from 

 the valley floor. All the fossils in this locality come from a 

 hard compact sandstone that weathers w r ith a brown concentric 

 stain, which makes a lithologic character that is very constant. 

 Above the Cretaceous there is a blue shale, probably middle or 

 lower Miocene, which is apparently conformable in dip, but 

 not so in reality. The unconformity is shown by the lack of 

 Eocene sandstone which is present in Arroyo del Valle, Mt. 

 Diablo section, several miles east of this place, and by a varia- 

 tion in the level to which the Cretaceous floor was reduced by 

 erosion, previous to the depositions of Miocene. In the Milpitas 

 locality, the Miocene overlies beds containing Aucella Pioclii 

 of the lower Knoxville, and in the Pleasanton region it overlies 

 beds containing Aucella crassicollis of the Upper Knoxville in 

 one place, and Venus varians of the Horsetown in another. 



Beryessa Canyon. — In Beryessa canyon the fossils given here 

 have been found in a coarse conglomerate that is composed of 

 hard flinty shale nodules. 



Aucella Piochi Gabb 

 Phylloceras knoxvillense Stanton 



