304 Prof. Hitchcock on Ichnolithology, or Fossil Footmarks. 



Another of our associates, Dr. David Dale Owen, has recently 

 shown most conclusively, that the supposed human footsteps on 

 the limestone of the Mississippi valley, are of artificial origin. 

 This was a demonstration greatly needed ; since some distin- 

 guished transatlantic geologists were inclined to regard them as 

 the veritable footsteps of men, coeval with the rock that contains 

 them, although I am not aware that that opinion was ever adopted 

 in this country. 



Having thus brought up the history of ichnolithology to the 

 present time, so far as I know it, I proceed to detail some new 

 facts that have fallen imder my notice since the last meeting of 

 this Association, in relation to the footmarks of this country. 

 And first, I shall describe a few new species that have been found 

 on the sandstone of Connecticut River. 



The first is a large species of Ornithoidichnites, occurring upon 

 the hard impure limestone of Chicopee Falls in Springfield, along 

 with the Sauroidichnites polemarchius, minitans, and others. It 

 will be seen in the sequel, that some interesting facts are associa- 

 ted with this track. I dedicate it to my friend, William C. Red- 

 field, Esq., the successful investigator of our fossil ichthyology, 

 and ingenious expounder of the world's meteorology. 



DESCRIPTION. 



Ornithoidichnites Redfieldii. Toes three, all pointing forward, 

 spreading 70° ; leptodactylous, yet having claws from an inch to 

 an inch and a half long ; length of the middle toe and of the 

 foot, thirteen and a half inches ; length of the step, thirty inches. 

 Shown (of one fourth the natural size) on fig. 1.* 



Although I have seen several tracks of this species, I have 

 found only one example of them in succession, and therefore the 

 length of the step may not be given very accurately above. 



This is the first example in which I have found claws upon a 

 narrow-toed or leptodactylous track. And in this case the claws 

 do not appear upon the surface where the animal trod ; but upon 

 splitting off some of the rock beneath, through the layers that 

 were depressed by its weight, the claws are obvious. Copies of 

 the extremities of two of the toes of one track, with the claws, 



* All of the drawings on the Plate accompanying this article are reduced to 

 one fourth of the natural size. 



