96 FOSSIL FLORA OF THK JOHN DAY HASIN, OREGON. [m i.i.. JtM. 



leaves from the Masciill beds iue icfei-red to the well-known Miocene 

 C (jnoidis. 



Out of the vast number of leaves from Bridge Creek only two have 

 thus far been found which clearly Ixdont*- to Coi'i/Jnn J\f<ic(Ji(((rr!/, and 

 these ai'e not to be distinguished from h>a\-es of this species figured by 

 Heer from Alaska. There ean be no dou])t as to the correctness of 

 this identification. 



Betula, as alre;idy j)ointed out, is the most abundantly represented 

 of any genus in the tiora. />. hcferoiuorpha ?in(\. B. hrUrodonta are by 

 far the most abundant species. The first nunitioned was in part 

 described ))y Newberry, under the name of l\q)u1 >ix p()ly7n.<ii-_[>ha^ from 

 the resemblance to certain of the leaves of the living ]\ allxi^ but with 

 the great number of individuals at my disposal 1 can not l^elieve that 

 they should be refei'red to Populus, although the}^ do somewhat 

 resemble 1\ alha. Hardly to be separated from this is Newberry's 

 B. heterodonta, but in general it has much larger leaves, with coarser- 

 toothed margins, and a more markedly inequilateral base. Many of 

 the leaves of both species show evidence of having been attacked l)y 

 fungi, producing spots and punctures so characteristic of numerous 

 spot-producing fungi. As none of the essential features of these fungi 

 are preserved, no attempt has been made to describe them. 



Under the name of Betala Bendlrei I have ventured to describe a 

 single leaf that, while evidently allied to B. Jieteroinorpha, differs in 

 being nearly circular in shape, with an equal base and regularly 

 spaced secondaries. 



Almost equally abundant was the species of Alnus described l)y 

 Lesquereux as A. carjnnoides. It is contained in all the collections 

 from Bridge Creek, and has also been detected at several other locali- 

 ties within the basin. From a fragment of a single large leaf 1 have 

 characterized a new species under the name of A. iiiacrodonta. It is 

 broadly ovate, with abruptl}^ truncate and heart-shaped base and 

 coarsely dentate margin. 



To the Fagacese are referred a single very doul)tful leaf of Fagus 

 and no less than 17 species or forms of Quercus. The oaks, although 

 not quite so abundant in individuals as certain of the species of Betula, 

 Alnus, etc., above mentioned, are much more abundant in species and 

 in a few cases are nearly as numerous in individuals. The oaks are 

 divided sharply into two groups corresponding to the horizons in 

 which they occur. Thus 8 species are confined to the beds at Bridge 

 Creek and 7 species to the Mascall beds at Van Horn's ranch and 

 vicinity, and very few from either locality have been found be3^ond 

 the confines of the John Day Basin. 



The oaks from Bridge Creek are small, nonlobed forms, with entire 

 or serrate ijiargins. They are also in the main thick, coriaceous-leaved 



