Fossil Footprints of the Connecticut Valley. 167 



and of several varieties of birds. But the slabs also contain evi- 

 dences of a new quadruped, whose foot was two inches long and 

 consisted of ^ue toes. The impressions are numerous and dis- 

 tinct, showing the tuberous expansions of the joints, and in some 

 instances the terminal claws. Bat I have given the impres- 

 sions only a hasty inspection, and cannot be more definite until 

 they have been thoroughly considered. Every visit to the sand- 

 stone quarries discovers something new, and proves that this 

 rock, which has until recently been considered to be nearly des- 

 titute of the indications of organic life, except of fishes and a 

 few lignites, is rich in the evidences of ancient life. For some 

 reason not understood, this rock is unfavorable to the preservation 

 of bones of animals ; but it renders a full equivalent by retaining 

 the exquisite impressions of their feet, and in some instances of 

 their bodies. It is a mine of knowledge ; beyond the signs of 

 life hitherto described, many others are apparent, too vague to be 

 compassed by any laws of comparison that have yet been applied 

 to them. 



Note. — I cheerfully take this occasion to correct a statement 

 in my rejoinder to Prof Hitchcock's reply, (Vol. xlvii, p. 401,) 

 which does that gentleman unintentional injustice. In alluding 

 to the labors of Mr. H. in developing the history of footmarks, I 

 remarked that he was amply compensated therefor by virtue of 

 holding a geological commission from the state of Massachusetts. 

 I believed this to be strictly true ; but since the publication of the 

 controversy, I have received a note from him stating that his first 

 commission expired in 1833, and that his second was received 

 late in the summer of 1837 ; consequently for three summers 

 after the first discovery in the spring of 1835, he was not in the 

 service of the state. This explanation is due to Mr. H,, and the 

 mistake would have been corrected in the proper place if Mr. H. 

 had not accidentally failed to receive a proof of my piece. 



Greenfield, November 20, 1844. 



