diller.] MARINE DEPOSITS NEAR ORESCENT CITY. 33 
records finding 1 a Trochita, which agrees very well with the casts in 
the soft yellow shale. It came from the Contra Costa Miocene of 
Walnul Creek. All the California Trochitas are Miocene, but an 
Eocene species occurs in Alaska. Xo living Pliocene species are 
known, though the allied Gait rus occurs. Gabb says 1 that his shell 
was probably new, but he desired to await more material before 
naming it. It is probably of the San Pablo horizon." 
The material from these localities is so fragile and the fossils are so 
poorly preserved, especially in the weathered portion, that their age 
must be considered doubtful until a palaeontologist can study the 
fossils in the field and make out a fauna complete enough to give 
value to est imated percentages of living and extincl species. Xear 
the eastern limit of the Xeocene deposits found in Humboldt County 
about Bridgeville, and thus at least in a measure corresponding to 
those of the Wymer beds, are Miocene species. The beds of the 
Bridgeville region, except where lithified Locally by carbonate of lime, 
are very soft, like the Wymer beds. 
In the Wymer beds, near the fossil shells, were found a number of 
leaf impressions preserved in oxide of iron. These have been studied 
by Dr. F. II. Knowlton, who reports as follows: 
The material submitted is a loose, friable, highly ferruginous sandstone, not 
well fitted for retaining plant remains. The plants consist of leaves and fruits, 
but not a single example is preserved entire From a somewhat hasty study of 
these fragments I am able to identify with reasonable satisfaction the following- 
named species: Magnolia lanceolata Lesq., Persea pseudorcarolinensis Lesq., 
paurus salicifoliaf Lesq., and Quercus sp. 
These species, fragmentary and unsatisfactory as they are, seem to indicate 
that tlie beds in which they occur are of the same age as the so-called auriferous 
gravels. Magnolia lanceolata was first found in the Chalk Bluffs of Nevada 
County. Cal.. and I have recently obtained it from the Mascall beds of the John 
Day Valley, ( )regon. Persea pseudo-can >li ne u si ',s came first from Table Mountain, 
California, and has since been reported by Lesquereux from Corral Hollow. Cali- 
fornia, but of this latter determination I am uncertain. I am in doubt as to the 
leaf I have referred to Laurus salicifolia. Only a portion out of the middle of a 
leaf is present and the determination must be regarded as open to question. 
This species was originally described from Corral Hollow, California. 
From the evidence at hand it seems safe to say that the affinities of these beds 
are with the auriferous gravels, or Upper Miocene. 
In order, if possible, to determine more closely the age of the Neo- 
cene beds of the coast of northern California, Dr. Dall spent apart 
of the summer of 1001 in that region, and concerning the Williamson 
Barn locality he reports by letter of October 28, 1901, as follows: 
Find the excavation filled up and the locality so overgrown with brush as to he 
unidentifiable with exactness. But the same beds reach the surface at a point 
abottt one-fourth mile southwest by compass from Fred Wilkins's house on the 
brow of the hill west of Williamson's place. Here the removal of a few inches of 
i Pal. Cal.. Vol. II. p. i:.. 
I ill 11, J !)•'»— (H 3 
