352 Fossil Horse, 



which by detrition present disks, more or less resembling each 

 other in the teeth of these different animals. Thus, a superfi- 

 cial observer might readily confound our fossil tooth with that 

 of a young mastodon, was not its size at least one-half smaller 

 than the smallest of the milk molars of the mastodon that have 

 come under the observation of naturalists. Mr Cooper has 

 casually remarked (vid. Notices of Big-bone-lick. Am. Monthly 

 Joum. of Geology, p. 163, in a note), *' Among these (the 

 molars of the mastodon), I include one similar to the tooth, al- 

 so from Big-bone-lick, described by Dr Harlan, as having be- 

 longed to an extinct species of tapir. That it is a young mas- 

 todon's tooth, is evident, I think, from the milk teeth still re- 

 maining in the head on which the supposed genus Tetracaulodon 

 is founded, as well as from the small jaw above described.**' 



It is difficult to conceive in what manner '' the milk teeth 

 remaining in the head" of this or that animal, could prove any 

 thing concerning the nature of the tooth in question. Mr C. 

 probably means to say that he compared the tooth of my fossil 

 tapir with those in the jaws of young mastodons ; I also have 

 made similar comparisons, and have carried comparisons still 

 farther. Taking the disputed tooth in question to Paris, I 

 compared it in presence of naturalists skilled for their observa- 

 tion, with the teeth of the various tapirs preserved in Cuvier's 

 collection of comparative anatomy. The tooth in question 

 proves to have belonged to the anterior socket in the upper jaw 

 of a tapir. The size of the tooth and the form and structure 

 of its roots, distinguish it from those of the mastodon. 



Place in the Geological sci'ies. — Contemporaneous with the 

 fossil remains of the rhinoceros, elephant, mastodon, and other 

 pachydermatous quadrupeds. Hitherto the fossil tapirs have 

 been found only in Europe, whilst the recent species inhabit 

 only South America and Mexico, the peninsula of Malacca 

 and the isle of Sumatra. 



Genus Equus. 



E. caballm. The Horse. 



The fossil remains of this quadruped are sparingly found 



both in North America and in Europe. The late Dr S. L. 



Mitchell, in his edition of Cuvier's Theory of the Earth, alludes 



