1849.] ISl 



The superior fragment contains the three true molars and the last premolar. 

 The seventh, or most posterior molar, is fully protruded and well developed, and 

 the summits of its transverse eminences are worn sharp by trituration on their 

 anterior snrface. The penultimate molar has the enamel of its transverse emi- 

 nences worn through, leaving two transverse irregularly outlined surfaces of ex- 

 posed dentine. The antepenultimate molar, as usual in accordance with its order 

 of development, is smaller, and more worn than the premolar preceding it. Its 

 two transverse eminences are worn to their base, and the dentinal surfaces of each 

 communicate by a narrow isthmus. The posterior premolar is but a little more 

 worn than the penultimate molar. In comparing these teeth with those of two 

 adult crania, of the recent Tapirus Americanus, in the Academy's collection, [ 

 find that although they almost correspond in their antero-posterior measurement, 

 yet transversely they are somewhat larger, as may,be observed by the following 

 table : 



Tapirus Americamcs fossilis. 

 Molars. Giealcst Iraiisvprae diameter. Antero-posteriur diameter. 



7th 1.1-5 . . . . 1.1 



6th .... 1.2 .... 1. 



Olii • « • • J. • X • • • • •«? 



4th ... . 1.1 .... .8 



Recent T. americanus, adult. 

 7th .... 1. .... .9 



6th . . ^ . 1.1. . . . 1. 



5th ... . .95 85 



4th ... . .95 85 



The malar process of the fossil fragment is considerably more elevated above 

 the margin of the alveoli than in the recent specimens ; thus in the former, from 

 the margin of enamel on the neck of the penultimate molar to the mular process 

 at its posterior part where it enters into the composition of the orbito-temporal 

 fossa, it measures 1..3 in., whilst in the latter, from corresponding points, it 

 measures only .65 in. In the former also, the process curves upwards and out- 

 wards, whilst in the latter it forms a curve outwards, moderately upwards and 

 downwards. 



It also projects on a line posterior to the anterior transverse eminence of the 

 last molar, and not at the dividing line between the sixth and seventh, as in the 

 recent crania. 



The floor of the orbit is considerably more elevated than in the recent speci- 

 mens, being 1.9 in. above the enamel margin upon the neck of the penultimate 

 molar; in the other being 1.1 in. only. 



The depth of the orbital fossa, as forrned by the orbltar process of the maxillary 

 bone, has been the same in both the fossil and recent animal ; but the outer 

 edge in the former is elevated into a smooth rounded ridge, which either formed 

 the inferior edge of the orbit, or else bounded an external smooth groove about 

 two lines in depth and width, along the line of the maxillo-malar suture in the 

 recent cranium ; while in the latter, the edge of the orbit is formed by the malar 

 bone, and presents no groove internally alons; the sutures, except at its anterior 

 part, just external to the entrance of the infra-orbitar canal. The malar articu- 

 lating surface in the fossil, is therefore not only external to, but several lines 



