NEW SPECIES FROM THE SANTA LUCIA MOUNTAINS, 
CALIFORNIA, WITH A DISCUSSION OF THE 
JURASSIC AGE OF THE SLATES AT 
SLADE S SPRINGS 
CHARLES H. DAVIS 
It is proposed in this paper to give very briefly the results of 
studies of the invertebrate fauna of the Franciscan slates at Slate’s 
Springs, showing, first, that the fauna is older than the lower 
Knoxville, which itself is now being placed by many geologists 
in the Upper Jurassic (the slates, indeed, are much more faulted 
and metamorphosed than the sandstones of the Knoxville and dip 
under the Knoxville); secondly, that the fauna is not pre-Jurassic; 
and thirdly, that the molluscan fossils found at Slate’s Springs, 
and named in this paper, are closely related to the described forms 
from the Middle Jurassic of Cook Inlet and the Alaska Peninsula, 
and from the Jurassic of Queen Charlotte Islands. 
The locality under discussion is a narrow strip of seacoast 
extending from Point Sur southward to Slate’s Springs, a distance 
of eighteen miles. About four miles north of the springs, collec- 
tions of molluscan fossils and a few fragments of plants were made 
by Dr. H. W. Fairbanks’ and Mr. F. M. Anderson in 1894. These 
collections are now in part in the Leland Stanford Junior Univer- 
sity paleontological collection, and in part in the collection of 
the University of California. 
It has been the work of the writer to describe and name what 
are judged to be new species from the above-mentioned collections, 
and to make note of those specimens which are too poor to serve 
for the identification of species. The Sequoia fairbankst, described 
by Fontaine, is the only named fossil from this locality. The 
pecten from the San Luis formation of Fairbanks, and collected 
by him from a locality six miles north of Port Harford, San Luis 
Obispo County, is also described in this paper. 
8 eatery of the Southern Coast Ranges,” Jour. Geol., VI (1898), 551-76. 
453 
