GEOLOGY AND MINERALOGY. 319 



that we are induced to give insertion to a somewhat copious extract from a paper 

 on the subject, communicated to the Academy of Natural Sciences of Philadelphia, 

 by Messrs. F. B. Meek, and F. V. Hayden. The presumed Tertiary age of these 

 remains is disproved by the authors, on evidence of the most conclusive character. 

 The beds in which they occur are shown, in many places, actually to underlie 

 deposits containiug a»^w^o»^^^es(/) and inocerami[!) ; and these leaves, moreover, 

 differ completely from those belonging to the true Tertiary deposits of the country. 

 But we will let our authors speak for themselves : — 



The Cretaceous system, as developed in Nebraska, is clearly divisible into five 

 distinct formations, which have, for the sake of convenience, been numbered 1, 2, 3, 

 &c., from the base upwards. Although at first entertaining some doubts as to 

 whether No. 1, or the lowest formation, might not be older than Cretaceous, we 

 always placed it provisionally, in our own published sections, in the Cretaceous 

 system. More recently, after a careful review of the subject, we became satisfied, 

 from the modern afiinities of numerous dicotyledonous leaves found in this forma- 

 tion, that we hazarded little in regarding it as a settled question that it could not 

 be older than Cretaceous, and so expressed ourselves in our paper read before the 

 Academy of Natural Sciences, Philadelphia, March, 1858. 



The reference of this formation to the Cretaceous, however, was not without 

 some exceptions generally admitted, for Professor Jules Marcou, in his work on 

 the " Geology of North America," page 143, refers it to the New Red Sandstone, 

 and in a subsequent publication,* he places it in the Jurassic ; while some investi- 

 gators in this country also inclined to the opinion that it must be Triassic. In the 

 midst of these conflicting opinions, although satisfied we were right, we wished, in 

 order to remove all doubts from the minds of others, to have the opinion of some 

 good authority in fossil botany, (a department of palaeontology to which we have 

 given little attention,) respecting the fossil leaves on which we mainly based our 

 Tiews in regard to the age of this formation. Consequently, we sent outline sketches 

 of a few of them to Professor Oswald Heer,f the distinguished authority in fossil 

 botany at Zurich, Switzerland, infoming him they were from a formation we 

 regarded as Cretaceous, and requesting him to let us know to what genera and 

 geological epoch he would refer them. This letter was sent to Professor Heer in 

 August last, before we started to Kansas, and on our return, in the latter part of 

 October, we were disapointed at finding no reply from him. After waiting some 

 days longer, and receiving no answer from Professor Heer, we concluded our let- 

 ter had either failed to reach him, or that he was unwilling to express an opinion 

 based upon mere sketches of the leaves ; consequently we submitted the whole to 

 Dr. Newberry, who had then returned to Washington, and in whose opinion on 

 this subject we have the fullest coufidenee. 



After examining the specimens. Dr. Newberry gave us a written statement 

 bearing date Nov. 12, containing a list of the genera to whicii he had referred the 

 leaves, together with some interesting remarks and generalizations, in which he 

 expressed the opinion that they are certainly Cretaceous, some of them belonging 



* Notes pour servir a uue description geologique des Montagnes Eocheuses, page 30, 

 t Our friend Dr. Newberry was then in New Mexico. 



