'2 Later Extinct Floras of North America^ 



he was connected as Geologist and Naturalist with an explor- 

 ing party Bent ont by the War Department under command 

 of Lieut (now Gen.) G. K. Warren, Corps of Topographical 

 Engineers, U. S. A. 



In the great mass of interesting materials brought by Dr. 

 Hayden, were a number of angiospermous leaves obtained 

 from a red Bandstone lying at the base of the Cretaceous for- 

 mation at Blackbird Bill, in Nebraska. Outline sketches of 

 some of i!i"-' leaves were senl to the distinguished fossil Bot- 

 anist, Prof. Oswald lien-, of Zurich, Switzerland. By him 

 they were pronounced of Miocene age, and referred to the 

 genera La ■ •. Populus, Liriodendro7i, &c. ; a narrow lanceo- 

 late leaf, being considered identical with Laurm primi 

 Ung. ; a broad rounded one, with Populus /.<>'<■<. Ong., both 

 found in the Miocene of Europe. At the Bame time the fossils 

 themselves were submitted to me for examination, and, regard- 

 ing thi sailed Populua I nerically identical with 

 some large rounded leaves described by Zenker from the t 

 taceous Bandstone of Blankenburg, Germany, 1 considered this 

 florula as of Cretaceous age— confirming the conclusions of 

 M • -. Meek and Hayden, who on other evidence had referred 

 the deposit from which they came to that period. The plant 

 calhd Louyub primigenia by Prof. Beer, I considered a Salix, 

 and the other leavi representing the genera Platanus, 

 Populus, Fagus, Liriodendron^ Sassafras, Magnolia^&a. Un- 

 fortunately, Prof. lie. t had only Bketches, and those of bul 

 part of these leaves ; and while I had the specimens all before 

 me, I had no specimens of the Cretaceous flora of Europe, but 

 only figures and descriptions of the comparatively few leaves 

 u j > to that time found in this formation by Zenk< r, Dr. Debey, 

 nd others. I' was therefore quite impossible that we 

 ild then make an intelligent com pari on of the two floras. 

 I mized among these plant: bj Prof. Beer and 

 in\ (forthemosl part, living in our foi and largely 

 ■•■',■ M I lurope. It is not surprising, 



