14 CALIFORNIA ACADEMY OF SCIENCES [Proc. 47TH SER. 
resulting from their decomposition is usually adobe-like, and 
is favorable for the growth of stunted oaks and junipers, but 
for no other vegetation,—not even grass. 
In the midst of a zone of hills which are destitute of trees, 
this belt of brown shales sprinkled with trees is not hard to 
follow. The shales are usually clay-like and brown on the 
surface, though in good exposures they show a variety of 
colors, some of them being either red, white, or greenish. It 
was this member that was called, for convenience, in the for- 
mer paper, the “Kreyenhagen shales’. In some places the 
beds become sandy toward the bottom, but this is not a con- 
stant feature throughout their extent along the range. 
The Upper Sands.—The thickest member of the Eocene, at 
least where it is best exposed, along the Cantua creek in the 
vicinity of the Lillis ranch, is that which was formerly de- 
scribed as the “Domijean sands’. Its thickness was roughly 
estimated as 2500 feet, though it may be more. As far as 
observed, there is considerable uniformity in composition, 
though there are some harder layers of fossil-bearing rock at 
intervals. In general these sands are yellow in color, soft and 
crumbling, with a disposition to weather into steep scarps 1m- 
perfectly exposing the edges of the strata, which are often 
concealed by loose and sliding soil. 
Except in the harder fossiliferous beds and in some con- 
cretionary layers, the sands are but little consolidated. Their 
greatest development is to be seen along the Cantua and Salt 
creeks and southward in the vicinity of the Domengine ranch, 
whence the name. The thickness of these sands is variable, 
but it increases somewhat regularly toward the north. In the 
vicinity of “Oil City”, north of Coalinga, the thickness has 
been given as not over 350 feet, and a little north of the 
Domengine ranch as 1200 feet, while along the Cantua, it is 
not less than 2500 feet. Farther west it appears to again 
diminish though it extends at least as far as New Idria. 
The fossils so far collected in this horizon are typically 
Tejon, though some of the species are found in the Martinez. 
In the vicinity of “Oil City’, a hard layer at the base of the 
yellow sands yielded: 
