Miscellaneous, 75 



occupying the same region ; many, perhaps most, of the genera 

 being now represented in our forests — such as Liriodendron 

 JPlatamis, Acer, Fopulus, Salix, Alnus, Fagus^ d'c. These spe- 

 cimens have been collected in localities included between the 36th 

 and 41stparallesof latitude, but range from the Y4th to the 110th 

 longitude. Nowhere within this area have I yet detected any 

 traces of palms or any indications of a tropical climate. At the 

 base of the Yellow Sandstone series of New Mexico (Lower Ore" 

 taceous) I have found a varied and interesting flora, containing 

 Pterophyllum^ Nilsoniaj Camptopteris^ c&c, with a few An- 

 giosperm dicotyledonous leaves. This is evidently the point of 

 junction between the Cycadaceous flora of the Jurassic age and that 

 of the chalk ; for in the entire overlying Cretaceous strata, 4000 

 feet in thickness, though Angiospermous leaves are abundant 

 those of Gymnospermous plants were no where discovered, nor 

 any traces of palms, either leaves or stems. The sandstones of the 

 Cretaceous series contain immense numbers of silicified trunks, 

 but they are for the most part coniferous. 



4th. For the glimpses have I obtained of the tertiary flora of 

 North America I am mainly indebted to the kindness of Dr.Hayden 

 who has spent several years in most successfully exploring the 

 geology, botany, and zoology of the country bordering the Upper 

 Missouri. Among his rich collections are fifty or more species of 

 beautifully preserved fossil plants from the Miocene, which have 

 been put into my hands for examination, and of which descriptions 

 will be published, immediately after my return to Washington. 



Not having the specimens, or my notes on them, with me, I 

 can speak only generally of the flora they represent. T remember, 

 however, that they include species of Platanus, — one of which 

 closely resembles Unger's great P. Hercules, and is perhaps as 

 large ; Populus, Acer^ Castaneay Sajnndus, CarpinuSf JJlmus 

 Diospyros, Quercus, Salix, Taxodium^ and others which indicate 

 a flora in all its general aspects similar to that now occupying the 

 Valley of the Mississippi. A few plants in the collection would 

 seem to have required a somewhat warmer climate than that 

 which the localities where they are found enjoy at present ; but 

 there are no palms amongst thera, nor any of the tropical genera 

 Cinamonium, Sterculia^ Domheyopsh^ &c. so common in the Ter- 

 tiary strata of Europe. 



In the enumeration of the Miocene plants of the Pacific coast 

 given by Mr. Lesquereux I find also evidence of a marked and in- 



