220 On the Lower Cretaceous beds of Kansas and Nebraska, ete 
of this formation. Consequently, we sent outline sketches ofa — 
few of them to Professor Oswald Heer,* the distinguished ar 
thority in fossil botany at Zurich, Switzerland, informing him — 
they were from a-formation we regarded as Cretaceous; and 1 
questing him to let us know to what genera and geological epoch 
he would refer them. This letter was sent to Professor Heerin 
August last, before we started to Kansas, and on our returg, 
the latter part of October, we were disappointed at finding 00 
reply from him. After waiting some days longer, and receiv 
no answer from Professor Heer, we concluded our letter had 
either failed to reach him, or that he was unwilling to expres 
an opinion based upon mere sketches of the leaves; coms 
quently we submitted the whole to Dr. Newberry, who 
* returned to Washington, and in whose opinions on this subject 
; 
(18th of Dec.) a letter from Professor Heer, beating d a 
1 3 . ta ¥ 
we have the fullest confidence. 
genera to which he had referred the leaves, together with som 
interesting remarks and generalizations, in which he ex ressetl 
the opinion that they are certainly Cretaceous, some of them be 
longing to genera peculiar to that epoch, and that the whole 
belong to more highly organized plants than are known 
Triassic or Jurassic flora. . 
Knowing as we did that the rock from which these pam 
were obtained, beyond all doubt, holds a position beneatt, * 
least, eight hundred feet of Cretaceous strata, containing great 
numbers of Ammonites, Scpahites, Baculites, &e., it 0 pee 
never oncé occurred to us that any person might suppor” 
Tertiary. F mre 
About the thirteenth of November we sent on to the Ament! 
Journal of Science, a communication containing Dr. New with 
list of the genera to which he had referred these plants, rn 
some extracts from his remarks, all of which appeared 2% 
after we had corrected the last proof of this paper, 
* Our friend Dr. Newberry was then in New Mexico. Lig 
+ These were published i the last number of this Journal. — ae 
“he 
ad 
= 
