110 UNITED STxVTES GEOLOGICAL SURVEY— TERTIARY FLORA. 



senting to the naked eye the well-known characters of the wood of the Palms. 

 The collections of vegetable remains from the Raton Mountains are composed, 

 for more than one-half, of fragments of Palm leaves. In the Eocene flora of 

 the Mississippi, the proportion of Palms is quite as large, if not more, indi- 

 cating, it seems, a small but gradual increase in the degree of temperature 

 toward the south. We have, however, in the United States, specimens of 

 large fronds of Palms from Fort Union, near the southern limits of British 

 America, at about 50° of latitude north, and still higher, from Vancouver's 

 Island, at 52°, the same latitude where, as seen above, the limits of Palms 

 have been recognized in Europe at the Miocene epoch. From the Eocene 

 times, the Palms seem to gradually lose in preponderance in the subsequent 

 formation of this continent. No specimens of this kind of plants have been 

 seen at Evanston, Carbon, or the Washakie (Laramie) groups. One species 

 is represented in the Miocene of Oregon and one in the Pliocene of the 

 chalk bluffs of Nevada County, California, a formation from which we know 

 only fifty species of plants, whose characters indicate a climate analogous to 

 that of the Gulf shores, or of the American Southern Atlantic States, at our 

 time. Hence, a gradual diminution of atmospheric heat seems to have been 

 continued from the Eocene to the Glacial epoch, at least, in considering 

 the distribution of the Palms. 



FLABELLAEIA, Schp. 

 Flabellaria Ziiikenit, Heer. 



Plate IX, Figs. 6, 8. 

 Flalellaria ZinTcenii, Heer, Boernst. Fl., p. 11, pi. ii, figs. 3, 4.— Lesqx., Annual Report, 1872, p. 377. 



Eays linear, flat or obscurely carinate ; primary veins distinct, with four to six intermediate tbin 

 veinlets. 



I refer with some doubt to this species fragments of Palm rays found 

 altogether in great number, but in such small specimens that the characters 

 of the leaves are lefl indefinite. These rays, rarely conjoined, or generally 

 separated like blades of grass, varying from five to seventeen millimeters 

 in width, are flat, somcliraes convex, as in b, fig. 7, or obscurely carinate, with 

 thick primary nerves, slightly convex upon their surface, one to one and a 

 half millimeters apart, separated by four to six thin intermediate veins, accord- 

 ing to the distance of the nerves, and distinctly seen with the glass, as marked 

 in the same fig. 7 c, enlarged four times. The best of our fragments have 

 been figured here. Tiiough very similar to those which have been figured 



