MEMOIR OF EDWARD D. COPE. 403 
rocks, though to this statement there is one notable exception, the Per- 
mian. Ag early as 1852 Marcou had reported the existence of Permian 
rocks in Texas, and in 1858 Swallow and Meek and Hayden had found 
them in Kansas; but this determination was disputed, and some author- 
ities maintained that there was no well defined Permian in the United 
States. The controversy remained unsettled until the appearance of 
Cope’s remarkable series of studies upon the amphibia and reptilia of 
Texas, the Permian character of which he fully established, and he also 
determined the presence of Permian rocks in Illinois. These results 
were further confirmed by the researches of I. C. White and Fontaine 
upon the plants and of C. A. White upon the invertebrates. 
In the Triassic and Jurassic and older Cretaceous, Cope’s work con- 
sisted for the most part in the identification of those horizons in regions 
where they had previously not been known. He did not discover new 
formations or correct the reference of those which had been wrongly 
placed in the geological column. This work, though producing no start- 
ling results, was nevertheless of high importance, especially in the Cre- 
taceous, for the successive vertebrate faunas of the Cretaceous stages were 
very fully investigated. Cope was the first to discover Dinosaurian re- 
mains in the Laramie stage, and the first, I believe, to advocate the refer- 
ence of that horizon to the Cretaceous, a view which then ran counter to 
all received opinions upon the subject, but which is now well-nigh uni- 
versally accepted. It is hardly necessary to emphasize the value of this 
determination in giving a fixed point in those obscure formations which 
intervene between the typical Cretaceous and Tertiary. 
It was in the unravelling of the complexities of the fresh-water Ter- 
tiaries, which cover such vast areas in the west, that Cope’s most splendid 
services to geology were rendered, and the value of these services it is 
difficult to exaggerate. Tirst of all should be mentioned his discovery 
and identification of the Puerco, or oldest Eocene, which may fairly be 
called “ epoch-making.” Not only was a very extensive, entirely new, 
and highly significant fauna. brought to light, but also the existence of a 
long time-interval between the Laramie and the Wasatch was demon- 
strated, showing that the supposed continuity of sedimentation con- 
necting those horizons wasillusory. This discovery necessitated an entire 
change in the views concerning the geological history of the western re- 
gion in post-Cretaceous times. The Puerco carried the Eocene much 
further back than had been expected, and opened up a new world to the 
paleontologist. 
The succeeding Wasatch formation had been discovered and named 
by Hayden, but it is to Cope that we owe much the greater part of our 
knowledge concerning its distribution, its relations, and its place in the 
