ROCKS OF THE COAST RANGES OF CALIFORNIA 497 
very frequently the case with layers of volcanic glass and 
pumice. Overlying this basal volcanic series are some sandstone 
beds (4), which have offered the majority of the marine fossil 
shells from this locality. Lying upon fossiliferous sandstones 
are a set of blue beds (C), composed of volcanic conglomerate, 
tuff and sandstone. The tuffs and volcanic conglomerates are 
derived from andesite, containing hornblende and pyroxene. 
These andesitic tuff beds contain abundant silicified wood, and 
the first list of fossil leaves given below collected in 1886, came 
from a fine layer in this tuff series. 
These leaves were studied by Lesquereux, who published a 
list of the species identified in the proceedings of the U.S. 
National Museum (Vol. XI, 1889, p. 35), as follows. 
Fossil leaves from the San Pablo formation on the Hyde 
Ranch, collected in 1886. 
Diospyros virginiana 1, var. turneri, Lx. 
Magnola californica Lx. 
Laurus, ct. canariensis Heer. 
Virburnum, cf. rugosus Pers. 
Wats, spay (): 
These are considered to be probably Pliocene, although on 
page 11 of the same publication, the same collection is referred 
to the Upper Miocene. These leavés come from a fine layer in 
the blue andesitic sandstones which form a higher horizon than 
the bed which afforded the most of the fossil shells given in the 
previous list by Dr. Merriam. 
The leaves collected in October 1897, came from a bed con- 
formably overlying the blue andesitic sandstones, and underlying 
the volcanic pumice represented by specimens 345 (Series D). 
Immediately underlying the leaf layer, is a light colored layer, 
containing specks of pumice in which are fossil shells. One of 
these, is an Astrodapsis, as determined by Dr. Merriam, which 
is considered as characteristic of the San Pablo formation. 
This second set of leaves came from a higher horizon of the 
San Pablo formation than those collected in 1886. The leaves 
collected in 1897 were referred to Professor F. H. Knowlton 
