98 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4TH SER. 
lower fossiliferous beds of the series, but he was unable to 
arrive at any more definite conclusion than that the beds were 
of Middle Tertiary, or Miocene age. Whitney and Gabb 
came only to the same general conclusion as to their age. 
Dr. J. G. Cooper, after examining several small collections 
made by W. L. Watts, partly from the lowest horizon, though 
chiefly from one higher up, was able to classify the beds only 
as Neocene. Among the fossils from the vicinity of Barker’s 
ranch he believed he had identified many living species, and 
evidently these influenced his determination of their age. 
Later J. C. Merriam expressed a belief that the beds containing 
Turritella ocoyana and two or more forms of Agasoma, etc., 
were of Lower Miocene age, and refers to the Kern River beds 
as examples of the same. It is due also to remember that Dr. 
Merriam recognized the occurrence of many species in these 
beds having a modern or recent aspect. 
In accordance with the views already expressed in this 
paper, only the lower 2000 feet of strata can confidently be 
called Miocene, as only that part of the series is known to be 
fossiliferous. Within this range, fossils are found at different 
levels throughout the area, some species having the entire 
vertical range. Dosinia whitneyi, Chione temblorensis, Pec- 
tunculus septentrionalis, and Neverita callosa have been found 
at both the top and bottom of the fossil-bearing strata. Pecten 
andersoni, Venus pertenuis, and Solen sicarius have a consid- 
erable vertical range. But by far the larger number of species 
and individuals are found in a much more restricted range. 
There are, as already suggested, three well-marked horizons, 
separated by intervals of more than 400 feet, which contain 
nine-tenths of the fossils and an equal proportion of the species. 
These horizons have been designated as Zones A, B, and C. 
Zoue A is that of Pyramid Hill on the divide between the 
Kern River and Poso Creek. It is apparently the horizon 
described by Blake, and the one from which he collected the 
species described by Conrad, and it constitutes the lowest 
known fossiliferous horizon of the series. The top of Zone A 
is not more than 500 feet above the base. The beds are some- 
what concretionary and exceedingly fossiliferous. 
Zone B is that of the Barker’s ranch locality, best seen on 
the north bank of the river one mile above the old ranch house. 
