138 AN ATTEMPT TO DESCRIBE THE ANIMALS THAT MADE 



ed from the rocks, according to all the light that can be obtained. 

 If the zoologist can only be satisfied that the animal once existed, 

 and has not already been described, he feels justified in fixing upon 

 it a name, which shall serve, at least, till a better one can be 

 obtained. Why, then, should not the same principles guide us in 

 respect to the beings that produced the fossil footmarks ? Even 

 if we admit that there is more uncertainty in our conclusions 

 than in any case where a portion of the animal is preserved, 

 (which, I fancy, no one who studies ichnolithology will maintain,) 

 I do not see that the principle by which names are given is 

 different. 



Baron Cuvier has finely described the definiteness and certainty 

 with which we can infer the character of an animal from its track, 

 although when he wrote fossil footmarks were unknown. " Any 

 one," says he, " who observes merely the print of a cloven hoof, 

 may conclude that it has been left by a ruminant animal, and 

 regard the conclusion as equally certain with any other in physics 

 or morals. Consequently, this single footmark clearly indicates to 

 the observer the forms of the teeth, of all the leg-bones, thighs, 

 shoulders, and of the trunk of the body of the animal which left 

 the mark. It is much surer than all the marks of Zadig." 



In the sixth place, we have the highest authority for applying 

 names to animals whose tracks are the only evidence of their ex- 

 istence. 



This was done by Professor Kaup in the case of the Chirothe- 

 rium. True, Professor Owen has subsequently given the name of 

 Labyrinthidon to a batrachian whose bones he has examined, and 

 which he conjectures to have been identical with the Chirotherium. 

 But if I understand the rules of priority in regard to names adopt- 

 ed by naturalists, if no doubt exists as to the identity of the 



