GEOLOGICAL SOCIETY 



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nity to forward plaster casts of this jaw, to the Geolo- 

 gical Society of London, and to the Garden of Plants at 

 Paris ; and on his recent visit to the Jardin des Plantes, 

 he was somewhat surprised to observe that he had al- 

 ready been in some measure anticipated by a foreign na- 

 turalist. This museum already containing the plaster 

 cast of a portion of the lower jaw of a Mastodon, sent 

 from Germany to Baron Cuvier, soon after the comple- 

 tion of the last edition of his American Fossiles. This 

 specimen also contained the inferior tusk, about which 

 so much has been subsequently written on this side of 

 the Atlantic. The circumstance, however, elicited very 

 little attention from the French professors. Yet it is on 

 the existence of this inferior tusk in the jaw of the young 

 individual from Orange county, above referred to, that 

 the author has attempted to found a new genus of fossil 

 quadrupeds, under the name of " Tetracaulodon." 



Admitting that the genus had been established on a 

 solid basis, the name is not a proper distinction, as it is 

 equally applicable to the camel, hog, horse, deer, hip- 

 popotamus, fossil tapir &c. all of which possess "four 

 tusks" or tusks in each jaw. 



It further displays inattention at least, if not igno- 

 rance of established usages among naturalists, to found a 

 genus on the existence or absence of tusks in the lower 

 jaw, independently of any other specific differences in 

 the organization of other portions of the body. It is 

 well known that the males of some species of animals 

 possess tusks in one or both jaws, whilst the females of 

 the same species are destitute of these teeth ; just as 



