68 THE LATER EXTINCT FLORAS OF NORTH AMERICA. 



species of the latter genus in the floras of America and Japan gives reason 

 to suppose that this was an element in the old flora which spread from 

 America into Asia and Europe, and therefore gives a probability of its being 

 found in the Tertiary and even Cretaceous flora. 



Formation and locality : Cretaceous (Dakota group). Blackbird Hill, 

 Nebraska. 



Order FAGACE-ffi. 



Fagus cretacea Newb. 



Pi. I, fig. 3. 



Ann. N. Y. Lye. Nat. Hist., Vol. IX (April, 1868), p. 23 (named, but not specifically 

 described); Ills. Cret. and Tert. PI. (1878), PI. II, fig. 3. 



Leaves 2 to 3 inches in length, ovate in outline, pointed above and 

 below, petioled, nervation sharply defined, regular, lateral nerves parallel, 

 straight below, gently arched above, terminating in the margins, which are 

 sometimes gently undulate, the nerves terminating in the prominences of 

 the margins ; in other leaves the margins are quite entire and nothing of this 

 last-mentioned character is seen. 



Collected by Dr. F. V. Hayden. 



This pretty species is represented in the collection by but a single 

 specimen. This is, however, remarkably well preserved, giving the general 

 form and the details of nervation with great distinctness. From the char- 

 acter of the nervation I have little hesitation in referring it to the genus 

 Fagus. Some of the Rhamnacese, particularly species of Rhamnus and 

 Frangula, have leaves which would be very like the one before us if fossil- 

 ized ; but in the fossil plant the lateral nerves are sharply defined, numerous, 

 almost perfectly parallel among themselves, and run quite to the margins, 

 which are seen to be slightly waved, the termini of the nerves being most 

 prominent and the intervals between them forming shallow sinuses. In 

 Rhamnus, however, even in B. frangula, of which the leaves so much resemble 

 this, the margins are not waved and the lateral nerves do not terminate as 

 distinctly in them as they do in Fagus and in our fossil. 



A striking similarity may be noticed between some of the leaves of the 

 living Fagus sylvatica, and this, though there is no probability of that species 

 having begun its life so early in the history of the globe as the first part of 

 the Cretaceous period. The resemblance is noted only as giving good 



