VIII. 
Illustrations of Fossil Footprints of the Valley of the Connecticut. 
By JAMES DEANE, M. D. 
(Communicated to the Academy, August 8th , 1849.) 
The beautiful footprints upon the sandstone strata of Connecticut River were 
discovered in the year 1835. They indicate the existence of vertebrated, air-breathing, 
and warm-blooded animals at a remote period of the earth’s geological antiquity; com¬ 
prising at least two classes of the animal kingdom, Aves and Reptilia. 
The number and perfection of these remarkable relics, the huge size of many of the 
creatures by whom they were impressed, and the consideration of the remote epoch 
in which they lived, invest the subject with intense interest. To myself, their study has 
for many years been in the highest degree attractive, and my labors in the field have 
invariably been compensated by successful discovery. As a result of the investigation, 
I respectfully offer this brief memoir. I have no intention of entering fully into the 
subject; my plan is merely to present some obvious practical views, grounded upon 
facts, leaving purely speculative conclusions out of the question. I do not even attempt 
a classification of the footprints. The creatures that made them existed in immense 
numbers, and unquestionably belonged to numerous families, genera, and species; yet to 
distinguish them all by strict rules of classification is absolutely impracticable. . The 
forms of the footprints are extremely diversified, even in unblemished impressions, and 
glide into each other by insensible gradations. But insurmountable obstacles are pre¬ 
sented in the various conditions of the stratum at the time the animal walked over it, 
and in the changes which the tracks must have, in many cases, subsequently undergone. 
If the surface whereon the creature trod was consolidated by desiccation, a superficial 
flattened impress resulted; if yet too soft, the impression must have closed in; and be¬ 
tween these extreme conditions there are infinite modifications of form. I apprehend 
that another difficulty in the way of classification arises from the fact, that the footprints 
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