GEOLOGY. 183 



preserved in cold countries that they are employed for the 

 same purposes as ivory. 



GENUS MASTODON. 



These animals had feet, tusks, trunk, and many other de- 

 tails of conformation in common with Elephants. They dif- 

 fered from these in the jaws; where the crown, bristled at its 

 issuing from the gum with thick conical points, presented, in 

 proportion to its detrition, disks more or less wide, which 

 represented the cups of these points. Remains of these ani- 

 mals have been found in both continents. The most remark- 

 able species, and one which appears peculiar to America, is 

 the great Mastodon, whose height is about nine feet ; the 

 proportions of the body are more heavy than those of either 

 the Fossil Elephant or the Elephant of our days. There 

 was an error in regarding it as carnivorous. 



GENUS RHINOCEROS. 



There were three large Rhinoceroses, all two-horned. 

 The species most widely scattered, in Germany and England, 

 and which, like the Elephant, is found even near the shores 

 of the Frozen Ocean, where it has also left entire individuals, 

 had the head elongated, the bones of the nose robust, sustained 

 by a bony nostril partition, not one simply cartilaginous ; it 

 was destitute of incisives. 

 * 



GENUS MEGATHERIUM. 



This united a part of the generic character of the Arma- 

 dillo with some of those of the Sloth, and in height equalled 

 the largest Rhinoceros ; its claws must have been of a mon- 

 strous length and strength ; all the skeleton is of excessive 

 solidity. As yet none have been disinterred except in the 

 sandy strata of South America. 



POST-DILUVIAL EARTH. 



This earth comprehends the products of present volcanoes r 

 glaciers, morasses, deposits of lake salt, modern formations 

 of sand and calx, fluviatile and marine alluvions, deposits of 

 springs incrusting banks with Mollusca and Zoophytes, 

 flinty and muddy deposits, and finally modern turfs, and the 

 vegetable mould. The organic remains here met with belong 



