14 



size. The subsequent discovery of the remains of two species 

 of the closely allied extinct genus Hipparion, in addition to the 

 discovery of remains of two extinct equine genera of an earlier 

 geological period, leaves no room to doubt the former existence 

 of the Horse on the American continent, contemporaneously with 

 the Mastodon and Megalonyx: and man probably was his com- 

 panion." 



The result of the whole seems to be, that of the 

 animals found fossil in the post-pleiocene beds, all 

 the mollusca of the present day are undoubtedly a 

 perpetuation of the same species; that of the high- 

 er order of vertebrata, the tapir, peccary, raccoon, 

 opossum, deer, elk, and musk rat are equally enti- 

 tled to be considered the descendants of this ancient 

 race. And if the claims of the mollusca to this dis- 

 tinction rests upon a secure basis, because they are 

 peculiar to this country, and not obnoxious to suspi- 

 cion ■ of foreign immigration, it must be recollected 

 that this is equally true of the above named animals. 



Those which have hitherto been regarded as of re- 

 cent and European origin, are the horse, sheep, hog 

 and ox ; and it must be reserved perhaps for future 

 consideration to determine how far the negative 

 proof of the non-existence of these animals in the 

 country at the time of its discovery may be regarded 

 in each individual case sufficiently strong to settle 

 the question of his extinction and re-introduction, 

 when so many of his associates and contemporaries 

 have succeeded in maintaining an unbroken line of 

 descent down to the present day. 



By the steamer Isabel, just arrived from Key West, 

 (March 1st) I received the annexed letter from the 

 learned Professor Agassiz, to whom I had the pleas- 

 ure of exhibiting these interesting specimens, only a 

 few days ago, when he passed through Charleston, 

 en route for Key West : 



