340 OLDER MESOZOIC FLORAS OF UNITED STATES. 
uary 31, 1895, to the Director of the Survey, transmitting it, Mr. 
Turner says: ‘‘The age of the slates from which the specimen came 
is Jurassic (Mariposa formation).” 
In the early part of October, 1895, I joined Mr. Turner’s party for 
a time while operating in this same general region, having with me 
Mr. James Storrs, who was with Mr. Turner at the time the fern was 
collected, although neither of them were with Mr. Oliver when he 
found it. Still, the exact gulch in which it was found was known to 
Mr. Storrs and we made a prolonged search for additional material. 
The shales are so transformed that scarcely any impressions are 
retained and we were mainly unsuccessful, but did find a few faint 
impressions of a vegetable nature, one of which was a fern nearly as 
well preserved as the original specimen. All this material, including 
the original specimen, was sent to Professor Fontaine, who reports 
upon it as follows: 
I have examined the specimens of fossil plants collected from the Mariposa slates, 
near Princeton, California. They are very few in number and very fragmentary and 
poorly preserved. The plant fragments before entombment had evidently drifted 
some distance. It is therefore not possible to make positive determinations. 
The specimen collected by Mr. Oliver, of Mr. Turner’s party, in 1894, from Yaqui 
Gulch, Mariposa County, shows the end of an ultimate pinna of a fern. Several 
pinnules on each side of the rachis and the terminal one are preserved. No fructifi- 
cation is shown. The pinnules indicate that the plantis a Dicksonia. It agrees very 
well, so far as the character is shown, with D. Saportana Heer,' from the Jurassic of 
the upper Amur of eastern Siberia, and may be provisionally identified with that 
species. ' 
One of the specimens collected by Messrs. Ward and Storrs in 1895, at nearly the 
same place as the last, shows the terminal portion, in a small fragment, of an ulti- 
mate twig of some conifer. It has several leaves of thick texture placed in two 
ranks on each side of the stem. They are widest at base, and decurrent, while they 
narrow to an acute tip. The terminal portion of the leaves is strongly incurved after 
the fashion of Pagiophyllum, to which genus it seems to belong. It resembles the 
specimen of P. peregrinum, given by Saporta in Paléontologie Francaise, Végétaux, 
Plantes Jurassiques, Tome III, Atlas, pl. clxxvi, fig. 3, and may be doubtfully iden- 
tified with that species. 
_ There is one other very problematic plant in that collection. It is a small bit of 
a twig, carrying on one side three small round bodies, which may be the cones of 
some conifer. They may be those of Leptostrobus. The mode of attachment and 
form indicate this, and the plant, for the sake of a name, may be called Leptostrobus ? 
mariposensis Font. n. sp. 
The above form all the identifiable plant impressions in the material sent. 
THE OROVILLE FLORA. 
On the 9th of October, 1894, Dr. T. W. Stanton, assisted by Messrs. 
Storrs and Oliver, made two small collections of fossil plants from the 
blue gold-bearing shales on the Feather River, in Butte County, Cali- 
fornia, 4 miles above the town of Oroville, the true age of which was 
1 Heer, Flora Fossilis Arctica, Vol. IV, Pt. II, pp. 89, 90, pl. xvii, figs. 1, 2; pl. xviii, figs. 1-3. 
