THE FOSSIL FOOTMARKS OF THE UNITED STATES. 139 



Chirotherium and Labyrinthidon, the former name must be 

 retained, and the latter dropped, and Professor Owen's right to 

 apply another name depends solely on the doubt of their identity. 

 And should that identity be hereafter made out, I do not see why 

 his name ought not to be superseded by that of Professor Kaup. 

 At any rate, I have never seen any intimation from the naturalists 

 of Europe, that the latter had not good grounds for giving a name to 

 a track-discovered animal. 



A second example may be derived from Professor Owen. In 

 his Report on British Reptiles, he gives the name Testudo Dun- 

 cani to the animal that made the tracks on the new red sandstone 

 of Scotland, which were described by Dr. Duncan in 1828. And 

 in doing this, who can show, — who in Europe has attempted to 

 show, — that Mr. Owen has not strictly conformed to the rules of 

 zoological nomenclature ? 



Finally, convenience in description imperiously demands the ap- 

 plication of names to these vanished animals of a former world, 

 who have left only their footmarks behind. The naturalist cannot 

 intelligibly describe the different sorts of these tracks, without giv- 

 ing to them distinctive characters; and unless he regards them all 

 as varieties of one species, — which no scientific man will do, — 

 how can he speak of them without the most inconvenient circum- 

 locution, if he affixes no names either to the tracks or to the ani- 

 mals ? Until he do this, he will find himself in inextricable em- 

 barrassment. 



Upon the whole, I am led to the conclusion, that, in attempting 

 to devise and affix names to the animals that made our fossil foot- 

 marks, if not to the tracks themselves, I am conforming to the 

 strictest scientific principles. I may fail in drawing out their dis- 

 tinctive characters correctly; I may mistake varieties for species. 



