STRATIGRAPHY OF CALIFORNIA COAST RANGES. 431 
capping the high mountains between it and the Manzana River, 
is a large area of light yellow sandstone, apparently not greatly 
disturbed. Continuing up the Sisquoc these sandstones were 
finally observed outcropping on the bank in direct contact with 
the Cretaceous. The discordance in dip of the two formations 
is about 15°. There does not seem to be any doubt about 
the reference of the sandstones to the Miocene, as they corre- 
spond exactly to the known Miocene only a short distance to 
the north. In the lower end of the Cuyamas valley are hori- 
zontal strata of incoherent sandstones bearing Ostrea titan and a 
species of Pecten, while only a short distance below are steeply 
inclined conglomerates and sandstones referable to the Chico. 
In a small tributary cafion of the Santa Ynez River, below 
the old Mission, is a contact between a body of dark shales, 
closely simulating the Knoxville, and light yellow sandstone. 
The sandstone rests on the shales with a discordance in dip 
of 200; ) Im ‘the’ shales ‘no ‘tossils: were found, but in the 
sandstone two species were obtained: Ostrea panzana (?) Con., 
and Pecten pabloensis (?) Con. That portion of the Santa Lucia 
Range lying in southern San Luis Obispo county consists largely 
of heavy-bedded sandstones and conglomerates, which according 
to our present knowledge are wholly referable to the Chico. 
Near the head of the Santa Margarita Valley specimens of 
Trigonia evansana, Gabb, and Axzinea veatchi, Gabb, were obtained 
from the sandstone. Five miles farther north several specimens 
of Venus lenticularis, Gabb, were found in a nodular mass of lime- 
stone in the same sandstones. 
An excellent section of the Bituminous Slate series (Miocene) 
is shown for many miles along the Arroyo Grande which has its 
source in the Santa Lucia Range. Near its head in the vicinity 
of Music are extensive beds of sandstone carrying Ostrea titan, 
Con., and Astrodapsis whitneyt, Remond. | Fully 2000 feet below 
this sandstone in the same series of rocks is a considerable 
thicknesss of soft argillaceous sandstone containing the follow- 
ing Miocene species: Pectunculus patulus,Con., Leda ceélata, Hds., 
and Arca microdonta, Con. Between 200 and 300 feet below 
