12 FOSSIL FLORA OF THE SIERRA NEVADA. 
the lower part of Fig. 5 is only half the length of that of the leaf, as 
it is also in the specimens figured by Heer. The larger leaves are seven, 
palmately nerved, the lowest veins open and thin, mere marginal vein- 
lets; the middle ones of an intermediate size and divergence, the upper 
ones ascending in an acute angle of divergence to at least the three 
fourths of the laminas, either inclining toward the borders, or toward the 
midrib, which they nearly equal in size, and always branching outside ; 
the secondary veins are few, and at a distance from the primary ones. 
As marked in Fig. 2, the areolation is formed by division of the nervilles 
in right angle, forming large subquadrate meshes, which, subdivided in the 
same direction by thinner veinlets, result in a very small ultimate irreg- 
warly quadrate reticulation. The various forms represented upon our 
plate are identical with those of the Baltic Mioc. Fl, Pls. V. and VI., 
agreeing equally well with those of the specimens from Greenland, Spitz- 
bergen, and Alaska. 
This species seems especially a representative of the Upper Miocene. 
We have it from the Green River group of the Rocky Mountains, but 
it has not been seen at Carbon, or in any other station of the American 
Lignitic. 
Habitat. — Chalk Bluffs, California. Professor J. D. Whitney’s, and Voy’s 
Collections. Fig. 6 is marked Roach Hill, Oregon. 
PLATANUS, Linn. 
Platanus appendiculata, sp. nov. 
Pl OT. Figs; 1-6.) PL Vi agi 
Leaves membranaceous or subcoriaceous, variable in size, either very large, widening up- 
wards, fun-like, abruptly curving and decurving to the petiole ; or smaller, broadly 
obovate, rounded or subtruncate to a short point, wedge-form to the base, distantly 
dentate by short flat teeth ; stipules double, leaf-like at the base of the short petiole. 
These remarkably fine leaves seem at first to represent two species, 
the one, Fig. 1, with very large, fan-like leaves, rapidly narrowed down- 
ward, and decurrent to the petiole, truncate or rounded at the top, with 
the borders marked by distant short teeth, separated by nearly flat or 
concave sinuses. This leaf, the only one seen of this size, is at least 
twenty-three centimeters long, twenty-four centimeters broad in its upper 
part, with a very long thick midrib, four millimeters broad at the base. 
