354 ON THE FOSSIL BONES OF PACHYDERMATOUS QUADRUPEDS. 



upper teeth, by the want of a fang. The lower jaw of Baldassari re- 

 duces this to an absolute certainty, for we have there this tooth of six 

 denticuli in its place, and without a fang. 



The posterior-superior is now the only tooth remaining to complete 

 our knowledge of the jaw-teeth of this animal. 



• It is not very difficult to perceive that it is the tooth of Trevoux 

 (plate 26, fig. 5). It is nothing more than a germ, still unimpaired 

 and without roots. It is 0,185 long, 0,08 broad, and 0,06 high, from 

 the neck to the top of one of the denticuli. Five deep furrows divide 

 it into six rows of prominences, each of which, except the last, is 

 subdivided into two. The partial prominences on one side have in 

 front a protuberance, which must necessarily have given them a trefoil 

 shape had the tooth been half worn. Those of the opposite side would 

 have remained elliptic. Hence the latter are the interior. The last 

 prominence or fang is a large uneven papilla, surrounded by others of a 

 smaller size. 



There is then a fang or an uneven collection of prominences in this, 

 which are not on the posterior-inferior tooth. And this is an additional 

 circumstance analagous to what obtains in the hippopotamus, and a 

 relation with the superior middle tooth. 



All these teeth, when compared one by one M^th the corresponding 

 teeth of the great mastodon of Ohio, present us with a very strong 

 characteristic, of which I shall avail myself for denominating this 

 species : it is this, that they are much more narrow in proportion than 

 they are long. 



Havino" once ascertained these characteristics, I have had no difficulty 

 in recoonizing isolated teeth or their fragments belonging to this 

 species, when they have presented themselves to my view. 



Figure 7, of plate 29, is a posterior-superior, preserved with its 

 congeneric in the cabinet of the late M. Baldovinetti, of Leghorn. 

 Though very similar to that of Trevoux (plate 26, fig. 5), its protuber- 

 ances are a little smoother, and its fang is more prolonged : it is 0,248 

 long, and 0,096 broad in its centre (marked cf). 



Figure 3, of plate 26, is the anterior half of a superior-posterior 

 from the cabinet of M. Dree, the denticuli of which are only just 

 beginning to be impaired. The roots are not developed. 



Fio-ure 7, plate 28, is one nearly similar, in which the fang alone is 

 a little more worn. 



Figure 10, plate 27, is one from the collection of M. Hammer, more 

 advanced in detrition, and with more strongly developed roots. 



Fio-ures 1 and 2, plate 29, is in a similar stage. It was found at 

 Rochetta di Tanaro near Asti, and belongs to M. d'Incisa of Milan. 

 M. Faujas has given me a drawing of it : it is as white as wax. 



Figure 6, plate 26, was brought from Peru by Dombey. Detrition 

 is here very forward in front, while it has not commenced behind, a 

 circumstance for which I feel at a loss to account. 



Fio-ure 13, plate 27, was found in the Val d'Arno, and presented by 

 M. Fabbroni. It is the posterior part of one which has not been worn' 



Fissure 8, plate 27, was found in the Val d'Arno. It is the posterior 

 part of a lower back tooth, not much worn. 



Figure 3, plate 29, is the same part but more worn, preserved in 



