379 
attrition ; so that, although no doubt could be entertained of its 
having belonged to an animal of the genus Mastodon, I think that no 
opinion could be formed respecting its species ; but on this point I 
speak with hesitation, since, at the time I saw it, I was unacquainted 
with the existence of more than one species of this fossil. 
LETTER XXVIII. 
FOSSIL REMAINS OF THE RHINOCEROS FOSSIL ANIMAL DIF- 
FERENT FROM THE RECENT SPECIES HIPPOPOTAMUS FOSSIL 
REMAINS SMALL FOSSIL HIPPOPOTAMUS, AN UNKNOWN SPE- 
CIES FOSSIL ANIMALS APPROACHING TO THE TAPIR. 
An accurate knowledge of the anatomy and of the number of species 
of the rhinoceros has been but lately obtained, and that through the 
assiduous inquiries of Cuvier. Thus the celebrated Camper, unac- 
quainted with the characteristic differences of the teeth of the unicorn 
and bicorn rhinoceros, and not finding incisive teeth in the two-horned 
species, charged Parsons, Linnaeus, and Buffon, with error, in suppos- 
ing them to exist in the one-horned species. But, on examining the 
living animal of the latter species at Paris, and seeing its incisive teeth 
he immediately acknowledged the error into which he had fallen 
M. Faujas also, for want of correct notions respecting the teeth of this 
animal, formed erroneous conclusions as to the number of species 
In every adult rhinoceros there are twenty-eight grinders, seven on 
each side, at the top and bottom. It must be, however, remembered 
that, as the teeth of the rhinoceros, like those of other herbivorous 
