444 THE JOURNAL OF GEOLOGY. 
University, and in the ridge through which is cut the San Fer- 
nando tunnel in Los Angeles county. 
Fifty-two species of fossils were found in the coast area of 
which eighteen are not known living, and four are not known in 
the present fauna of the same region. Using the old method of 
percentages we find 56 per cent. of the fossil fauna in the living 
fauna. It is found that twenty-two of the forms have been 
found in strata whose Miocene age is not questioned, of which 
number five are strictly Miocene. This would place these strata, 
according to some authorities, in the lower Pliocene; according 
to others, in the Upper Miocene. We do not as yet feel sate in 
asserting the identity of any of these species with those found 
in the Atlantic Miocene. In many cases, however, the resem- 
blance is so strong that for all practical purposes we may assume 
them to be of the same type, and use them as though we felt 
sure of their specific identity. 
The strata, like the Atlantic Miocene, are characterized by 
many huge Pectens, large Arcas, and other forms which have no 
representatives in the present waters of the coast. Thus, there is 
on the coast of California one very small species of Arca, found 
at San Diego. In these strata we find great numbers of several 
species of Avca, some of which are over four inches broad. The 
most common of these, the Avca microdonta, Conrad, will fit the 
figure and description of Arca arata, Say, of the Maryland 
Miocene just as well as it does Conrad’s figure and description 
of the west coast species. The presence of the large Pectens, 
Six or seven inches across, gives the fauna a strong resemblance to 
the Atlantic Miocene of Virginia and Maryland. Aside from the 
above localities these Pectens have been previously reported only 
from strata generally recognized as Miocene. The Crepidula 
grandis, Midd, is another form about four times as large as any 
of its living representatives. Many other interesting forms 
might be mentioned. It is thus seen that the fauna, while 
closely related to the living fauna, as shown by the percentages 
given above, has quite a number of species closely resembling 
species which, in eastern America, are typical of the Miocene. 
