62 MEMOIRS OF THE CARNEGIE MUSEUM 
ceous times the appearance of a low and comparatively level plain, with numerous 
lakes, both large and small, connected by an interlacing system of river channels. 
The whole, when covered over with luxuriant forests and broad savannas, made 
possible by the supposedly tropical climate of those times, would form an ideal 
habitat not alone for the large Dinosauria, but for the smaller reptiles and diminu- 
tive mammals of those days and for the fishes, mollusca and other aquatic life as well. 
In Figs. 25 and 24 respectively, are reproductions of photographs of a footprint 
from the dinosaur beds near Canyon City, Colorado, and ripple marks from the 
same deposits along the base of the Big Horn Mountains in Wyoming. 
Fic. 24. Photograph of ripple marks on surface of Jurassic sandstone, Big Horn Mountains, Wyoming. 
In Fig. 25 there is given the reproduction of a photograph by Dr. E. H. Barbour 
of the locality near Canyon City, Colorado, where were located the quarries so long 
worked by Professors Marsh and Cope. The dark area in the middle foreground 
just back of the tent is the quarry so long and successfully worked by Professor 
Marsh and recently worked with equal success by Mr. Utterback for the Carnegie 
Museum. At A directly across the cafion and on about the same horizon was 
located another quarry also worked with some success by Marsh. At B a little 
above and on the same side of the small cafion, but in a slightly different horizon, 
