294 Prof. Hitchcock on Ichnolithology^ or Fossil Footmarks. 



Batrachians. He regards them as having been produced by four 



species. 



The first account of the fossil footmarks on the new red sand- 



stone of Connecticut river, was published by me in 1836, in the 



January number of the American Journal of Science. Seven 



species only were described, of which live were three-toed, and 



two species four-toed. Two species were pachydactylous , or 



thick-toed, and five leptodactylous, or narrow-toed, the difference 



the 



These tracks were 



boldly, perhaps rashly denominated Omithichnites, or stony bird 

 tracks. But when I came to give an account of a much larger 

 number of species, in my Final Report on the Geology of Massa- 

 chusetts, I changed this name to Ornithoidichtiites, or tracks re- 

 sembling those of birds; and Saurioidichnites, or tracks resem- 

 bling those of Saurians, as more in conformity with the cautious 

 spirit of true science than the former name. 



My Final Report was published in 1841; and having in the 

 four preceding years devoted much time and attention to the sub- 

 ject of footmarks, I was enabled to describe and figure of the nat- 

 ural size in that work, no less than twenty seven species. At the 



meetin 



1842, 1 gave an account of five species more, and figures of these 

 also of the natural size, were given in the first volume of their 

 Transactions. In the present communication I propose to describe 

 four species more, although I shall be obliged to strike two from 

 the previous list, so that the whole number of species wnicn 

 consider established to the present time, is thirty three. 



It was to be expected that when it was announced that bir 

 tracks,— some of them four times larger than those made by t e 



11 A A Ad 



ostrich, — existed as low down as the new red sandstone, all g e 



• • They 



gists would receive the statement with great scepticism. x > 



would not have been true to their principles if they had suffer 

 any thing but the most overwhelming proofs to satisfy them. 

 no trace of birds had hitherto been found deeper than the Wea e 

 formation. I was well aware, when I first published on the su 

 ject, with what incredulity my conclusions would be viewed. 

 a person not familiar with the details of paleontology, there is 

 any thing very remarkable in the statement, that birds existe ^ 

 the period of the new red sandstone, and left their footma ^ n ,y 

 its layers; and accordingly, the community in general ha 



