182 [June, 



below the external edge of the orbitar process of the maxillary bone. This sur- 

 face is also directed a little more outwards, as it proceeds backwards, than in the 

 recent crania. 



The line of the malar articulation would cause the head to appear somewhat 

 broader opposite the temporal fossae, and the elevation of the malar process, and 

 of the orbit, would probably make the posterior part of the face appear higher in 

 the fossil than in the recent animal. But the differences which I have pointed 

 out, especially the generally vertical increase of diameter of the superior maxil- 

 lary bone in the fossil specimen, may probably be dependent upon the advanced 

 age of the individual, and the excessive development of the roots of the molars, 

 which is a common occurrence in some animals, after the body of the tooth has 

 been nearly worn down, as in the horse, &c. 



The left half of the inferior maxilla has the condyle, all the margin of the bone 

 below and posterior to it, and the coronoid process, broken off. As observed by 

 Dr. C, it belonged to an individual "just attaining to adult age," as is indicated 

 by its being about to lose the last of the temporary teeth, to be replaced by the 

 third permanent premolar, which latter, in the specimen, is exposed from the 

 former having been broken away. The sixth molar, or last true molar, is not 

 wanting, as supposed by Dr. C, but has not yet protruded from the jaw. The 

 roots only of the canines exist in the specimen. The incisors, except a fragment 

 of the root of the right internal one, as well as the exterior of the alveoli are 

 broken away; traces only of the alveoli of tlie lateral or most external incisors 

 exist. I can observe no difference of character between the specimen and the 

 recent jaw, except that the ridge occupying the interspace between the first pre- 

 molar, and the canine, is not so strongly curved as in the latter, making them a 

 very little, but to an unimportant degree, further apart. 



We have also in the collection of the Academy, the crown of a tooth ofTapirus 

 Americanus fossilis, deposited by Dr. M. W. Dickeson, and found by him near 

 Natchez, Mississippi. It is an inferior molar of the left side, apparently the 

 third temporary molar. Its transverse eminences are worn to their base. Its pro- 

 portions, and the fact of its being found associated with remains of Equus Ameri- 

 canus, Mastodon, Sec, are sufficient to justify the opinion that it is fossil, and 

 belonged to the same species as the inferior maxilla just spoken of. 



Dr. Harlan, in his Fauna Americana,* has described the superior left molar 

 tooth of a Tapir found in Kentucky, which he ascribes to a new species under the 

 name of Tapirus mastodontoides. Upon comparing his description with the fossil 

 fragments, and the recent specimens, I think there are not distinctive chai-acters 

 enough in it to distinguish it as a different species from the recent one, for the 

 greater obliquity of the transverse eminences of the crown, and the slight varia- 

 tion in the form of the disks occasioned by attrition, appear to me to be nothing 

 more than individual peculiarities. 



•p. 234. 



