50 FOSSIL FLOEA OF THE SIEEEA NEVADA. 



Pliocene of the auriferous gravel of California also, — show by their repre- 

 sentatives at other stations an uninterrupted relation to those of the present 

 times. In the Cretaceous we find four species of Sequoia, one Glyptostrobus, 

 and one Piniis. From the Eocene of Point of Rocks and Black Bntte, a 

 formation still considered by some geologists as Cretaceous, five species 

 of Sequoia and two Abietites are described. S. brevifolia is very closely 

 related to 8. Langsdorfii ; and this, found also in the Eocene, and more 

 abundant still in the Upper Miocene of Florissant, is, by the remarkable 

 affinity of characters, the ancestor of 8. sempervirens, the Redwood of 

 California, as S. affiius, also of the Upper Miocene, is that of 8. gigantea 

 (the big trees). At Carbon, and in the same Miocene formation near 

 Fort Fetterman, Taxodium distichum (miocenicum) abounds. Its name indi- 

 cates specific identity with the Bald Cypress of the Atlantic flora. 



I am forcibly limited here to this short review, where I cannot take into 

 account any specifications and enter into details which would render more 

 evident the relation of the present North American Eastern flora to that 

 of the geological times. But this is enough to prove that from the Cre- 

 taceous up there is no break in the chain which unites by links of succes- 

 sive modifications the types of the present vegetation with those of the 

 geological times. 



Professor Gray in his Memoir on the Botany of Japan, 1 considering a 

 few data derived from unimportant materials which I had obtained in the 

 Chalk Bluffs of the Mississippi, recognizes, by a remarkable prevision, 

 the ancient relations of the vegetation of the eastern slope of the conti- 

 nent. He says on the subject: 2 "Here may be adduced the direct 

 evidence, recently brought to light, of the presence of the Live Oak 

 (Quercus virens), Pecan (Carya oUvceformis), Chinquapin {Costarica pumila), 

 Planer-tree (Planera Gmelini), Hone}' Locust (Gleditschia triacanthos), Prinos 

 coriaccus, and Acorus calamus, besides an Elm and a Ceanothus, doubtfully refer- 

 able to existing species, — on the Mississippi, near Columbus, Kentucky, 

 in beds of a formation anterior to the drift, and whose position is indi- 

 cated by Professor D. D. Owen as about one bundled and twenty feet 

 below the ferruginous sand, in which the bones of the Mrgalonyx Jeffersorti 

 were found. All the vegetable remains which have been obtained in a 



1 Memoir on the Botany of Japan, ami its Relation to that of North America, in Mem. of the Amer. 

 Acad, of Arts and Sri., Vol. VI. p. 44 7. 



2 Airier. Journ. of Science and Arts, 2d Ser. No. SI, May, 1Sj9. 



