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ART. XV. — On the Sandstone Fossils of Connecticut River. 

 By James Deane, M. D. 



Prior to the year 1835, the indications of organic life, co-existing with the sandstone 

 deposition of Connecticut River, were exclusively confined to a few genera of hetero- 

 cercal fishes. This rock was formerly supposed to be so destitute of animal remains, 

 that when in this year I opened a new chapter of its organic history, my discoveries 

 were treated with incredulity and neglect. But, after the investigations of twenty 

 years that have resulted, it is known to be exceedingly rich in the imperishable 

 materials of geological history. Very few indeed have any conception of the 

 marvellous perfection of these fossil inscriptions, or of the multitudes of once living 

 creatures whose existence they commemorate. During the vast sandstone deposition, 

 it is presumed that animals whose instincts and organizations attracted them to littoral 

 margins, were as numerous as their living representatives. The immense groups of 

 birds embraced countless individuals who have inscribed upon the shores whereon 

 they congregated their unmistakeable and instructive history. Most of the finest im- 

 pressions have never been described, and the rich discoveries of late years, render a 

 thorough revision of these fossils indispensable to a clear comprehension of the sublime 

 truths they teach. 



Other inferior creatures existed in astonishing profusion during the sandstone 

 period, and like the birds, have left the imprints of their feet vivid as upon the day 

 they were made. The presumption is that they embraced as a class, animals no 

 higher in the scale of organization than vertebrated reptiles. They were quadrupedal, 

 and were grouped into several orders ; Saurians, Batrachians and Chelonians. Of the 

 saurian and batrachian orders I am acquainted with twenty species at least, and shall 

 present herewith a notice of ten of that number. In one essential feature all these 

 impressions concur, and that is, in the difference in magnitude between the anterior 

 and posterior feet, the latter being about four times greater than the former. This 

 distinctive character, and the diminutive size of the animals they indicate, appear to 

 distinguish them into species, having their affinities in existing salamandrian or tailed 

 Batrachians. 



The indications of Tortoises prove them to have been very numerous, but it is 

 nearly impossible to detect specific differences. Their movements over soft mud re- 

 sulted in ploughing up a trace or furrow by the solid armor of their bodies. In some 

 instances the swinging movements of their feet are well preserved, and in rare cases 

 the pedal imprints are also visible. 



