18 PACHYDERM ATA. 



species of this genus under the specific designation applied by 

 Pennant of E. Americanus? for which Adrian Camper, enter- 

 taining the same opinion of its generic relations, proposed the 

 substitution of E. macrocephalus. 2 But in his second extended 

 and elaborate memoir, published in 1805, which formed the ground- 

 work of what he has written on the subject in the ' Ossemens 

 Fossiles,' Cuvier separated the Elephants with mammillated 

 molars from the ordinary forms with lamelliform molars, and 

 united the former into a genus which he designated Mastodon, 

 taking the North American species, under the name of M. 

 giganteum, as the type. 3 In the interval between these 

 two memoirs, Peale made the important discovery of two 

 skeletons of the Ohio Fossil, near the banks of the Hudson River, 

 in the State of New York, one of which was brought to Europe 

 in 1802, and furnished nearly complete materials, for instituting 

 a detailed comparison between the osseous frame of the Mastodon 

 and of the existing Elephants. 4 Cuvier pointed out the entire 

 correspondence between them in the tusks, trunk, and the whole 

 of the skeleton, except the molar teeth. He admitted, even in 

 regard to the latter, that the difference between the transverse 

 mammillated ridges of the Mastodon, and the thin plates of the 

 Elephants, is merely one of proportion ; but insisted that there 

 is an essential distinction in the circumstance that the spaces 

 between the enamel ridges are filled with ' cement ' in the teeth 

 of the Elephant, which is wanting in those of the Mastodon. In 

 addition to this supposed difference, he found corresponding 

 modifications in the form of the cranium, which confirmed him in 

 his view of a well-marked generic distinction between Mastodon 

 and Elephas. 5 In the same memoir, Cuvier characterized four 



1 ' E. Americanus, inolaribus multicuspidibus lamellis post detritionem quadri- 

 lobatis." Cuvier, Memoir, de l'lnstitut. Ann. vii. (1798.) ' Sur les especes d'Eleph. 

 viv. et foss,' p. 21. 



A Camper, ' Descript. Anatom. d'un Elephant Male,' Avant Prop. Note, p. 10. 



3 Annales du Museum d'Histoire Naturelle, torn. viii. ' Sur le grand Mastodonte.' 



4 R. Peale, ' Account of the Skeleton of the Mammoth,' &c. ; and ' Historic. 

 Disquisit.' 1802 and 1803. 



5 Oss. Foss. torn. i. p. 221. 



