78 CALIFORNIA ACADEMY OF SCIENCES [Proc. 41H SER. 
in a wider study of the subject there appeared to be two 
distinct horizons of the Lower Miocene in California. 
In 1905 F. M. Anderson’ published a brief note on the 
formations along the Kern River, stating their thickness to 
be about 3000 feet, and giving a list of some 38 species, 
including many characteristic Lower Miocene forms. The 
species listed were all from the same horizon, within a vertical 
range of 200 feet, but more than 1000 feet above the base of 
the Neocene. 
Meanwhile Mr. John Barker, whose residence was for some 
years upon Kern River, collected a large number of fossil 
sharks’ teeth and other vertebrate remains from near the same 
horizon, all of which were donated to the California Academy 
of Sciences. 
Later F. M. Anderson collected an equally large number of 
similar remains from the same horizon, including many unde- 
scribed species, all of which were likewise donated to the 
California Academy of Sciences. 
In 1907 Dr. David Starr Jordan’ published descriptions of 
many new species of sharks and other fishes found in the 
collections of Barker and Anderson, but without any attempt 
to determine the exact horizon of the Miocene from which they 
were taken. In these collections there were nearly 800 speci- 
mens, representing perhaps 15 species, most of which were 
sharks, though including also remains of rays and skates. All 
of these collections were lost in the San Francisco fire. 
As will be seen from the foregoing review, the literature 
bearing upon these beds is fragmentary and scattered, and 
although the formations are interesting and important, no one 
seems to have found time to give them the attention they 
deserve. It is hoped that in the following pages the measure 
of their importance will be more fully shown, and some fur- 
ther information gathered from their study. 
TOPOGRAPHY OF THE AREA 
Viewed from a distance, the topographic features of the area 
herein described consist of low rounded hills, which taken 
altogether present the aspect of a gently sloping mesa inclined 
1 Proc. Calif. Acad. Sci. v. 2, pp. 187-188 
2 Bull. Geol. Dept. Univ. Calif. v. 5, pp. 95- Hoss 
