FOSSIL MAMMALIA. 



69 



fathoms in height, refers not only the mastodon, but the mam- 

 moth, to this fabulous monster. This confusion of the two 

 species probably made Mr. Jefferson think that the centre of 

 the frozen zone is the spot where the mammoth arrived at its 

 full perfection, as the countries situated under the equator 

 are the best calculated for sustaining the elephant. 



Let us now consider the osteology of the Great Mastodon, 

 beginning with the cheek-teeth, the most important character. 

 Their form is the most remarkable point about them. The 

 coronal approaches more or less to a rectangular figure. The 

 substance is two-fold, the ivory and the enamel. The latter is 

 very thick, but there is no appearance of that cortical substance, 

 so remarkable in the elephant. 



This coronal is divided by very open furrows into a certain 

 number of transversal prominences, each of which is itself di- 

 vided by a slope into two thick obtuse points, something like 

 quadrangular pyramids, a little rounded. Thus the coronal, as 

 long as it remains unworn, is furnished with thick points, dis- 

 posed in pairs. 



It will be seen that these teeth have no relation to the teeth 

 of the carnivora with one principal and longitudinal edge, 

 divided into notches like a saw. There is only a difference of 

 proportion between these transverse prominences, divided into 

 two points, and the little transverse walls, with edge divided 

 into many tubercles, in the teeth of the elephant. But in the 

 latter, the furrows which separate the prominences are filled 

 with the cortical substance, whereas, in the mastodon, they are 

 filled with nothing. From this it happens, that the coronal of 

 the elephant soon becomes flat from detrition, but nevertheless 

 remains always furrowed transversely, while that of the masto- 

 don is for a long time mammillated. Its protuberances be- 

 come at first truncated by detrition into a lozenge-form^ and 

 at last, when worn flat, its surface is perfectly even, or uni- 

 formly concave. 



The mastodon must have made the same use of its teeth as 



