1G4 UNITED STATES GEOLOGICAL SURVEY— TERTIARY FLORA. 



one of the Oregon species, is from the Upper Miocene of the Parks of Col- 

 orado. 



It is probable that if the fossil leaves of this kind were known from suffi- 

 cient specimens, the number of the species would be reduced; for the j)resent 

 flora has only two species: one, C. vulgaris. Lam., or C. vesca, is represented by 

 a number of marked varieties, often described as species, and distributed over 

 the whole temperate zone of the northern hemisphere, especially along the 

 shores of the Mediterranean Sea in Europe, Western Asia, North Africa, and 

 also in China, Japan, and the United States; the other, C. pumila, exclu- 

 sively belongs to North America. 



Castanea int e r media, Leaqx. 



Plate XXI, Fig. 7. 

 Castanea intermedia, Lesqx., Annual Report, 1874, p. 313. 



Leaf snbcoriaceous, long, narrow, linear-lanceolate, gradually narrowed downward; borders 

 equally sharply serr.ate ; secondary veins slightly curving, open, close, parallel, simple, and craspe- 

 dodrome. 



The fragment represents a leaf, long indeed comparatively to its width, 

 which is not much above two centimeters; while it appears to have been 

 more than twelve centimeters in length. The borders are sharply serrate, 

 the teeth turned upward, thorny-pointed, equal, and each entered by second- 

 ary veins, which are simple, close, about four millimeters apart, diverging 

 from the thick midrib at an angle of 50° to 60°. Every trace of areolation 

 is erased. Comparing this leaf to the other fossil species published, it differs 

 from all, being only related by its nervation to Castanea Ungeri, Heer (Fl. 

 Foss. Alask., p. 32, pi. vii, fig. 1), and even in our species the lateral veins are 

 still more numerous and more open. It has a more evident likeness to the 

 leaves of our present Castanea pumila, from which it would be undistin- 

 guishable, but for its linear form and the gradually tapering base. The 

 simple nervation, the degree of divergence of the veins, the form and sharp- 

 ness of the teeth, are all alike. The common C. vesca of the North has 

 longer leaves, more distant veins; but these leaves, at least when young, and 

 especially those of the bushy shoots, are gradually narrowed to the petiole, 

 and linear-lanceolate, like the fossil one. This therefore appears interme- 

 diate between both living species of North America. 



Habitat. — Middle Park, Colorado {Dr. F. V. Hayden). 



