DESCRIPTION OF SPECIES— CUPULIFEK^. 163 



]>ryopliylluin (Qiierciis) subfalcatum, Lesqz. 

 Plate LXIII, Fig. 10. 

 Dryophyllum subfalcatum, Lcsqx., Annual Report, 1874, p. 301. 



Leaf subcoriaceous, linear-lanceolate, narrowly taper-pointed ; borders regularly serrate, with 

 short blunt teeth turned upward ; lateral veins very oblique, close, parallel, straight to the point of the 

 teeth. 



We have only a fragmentary specimen of this species, the upper half of 

 a leaf, which, by its form and nervation, seems at first referable to the genus 

 Castanea or to some variety of the Chestnut-oaks. The nervation is of the 

 same character as in the former species, however, the upper branch of the 

 secondary veins passing from near the point of the veins under the sinuses 

 and closely following the borders, anastomosing with the fibrillge. These are 

 very close, percurrent, mostly simple, and rarely branching, distinct, though 

 thin. 



This species is intimately related to Dryophyllum Deivalquei, Sap. and 

 Mer. (Flore de Gelinden), especially to the fragment represented on pi. iii, 

 fig. 2, differing merely by the shorter, less acute teeth of the borders, the 

 slightly falcate form of the leaf, and the close, thin fibrillas. 



Habitat. — Point of Rocks, Wyoming {Mr. Wm. Clehurn).* 



CASTANEA, Tournf. 



The difficulty of discerning the fossil leaves of this genus from those of 

 Dryophyllum or Quercus renders uncertain the epoch to which its origin is 

 referable. 



One fossil species has been described by Dunker as Castanea Hausmanni, 

 from the Cretaceous Quadersandstein of Blankenburg, Hartz, where it is 

 found with leaves of Credeneria. On this species, however, Schimper observes 

 that it indeed resembles the leaves of C. vesca, the living species so widely 

 distributed in Europe and North America, but that it could just as well be- 

 long to Dryophyllum. From the Eocene of France, one species is described 

 by Watelet, another is from the Lower Miocene of Southern Europe, and 

 four are distributed in higher stages of the same formation. In this country, 

 leaves of one or perhaps two species of this genus are abundant in the Plio- 

 cene of Oregon. The fragment published here, and apparently identical with 



*To this section of Oaks is referable Quercug furdnervis, Eoesm., described in Aunnal Keport, 1873, 

 ji. 398, from very fine specimens of the Cascade Mountains of Oregon and of the Spanish Mountains of 

 California. The specimens belong to the Geological Survey of this last State, and are figured for its 

 Report. 



