ROOM VI. MASTODONS. 471 



long trunk or proboscis. The molars differ from those of the Elephant 

 in their simple crown composed of dentine and enamel, disposed in 

 large transverse tubercles, each of which is subdivided into two obtuse 

 points or mastoid processes, which by use are worn into disks more or 

 less wide, according to age ; these transverse ridges are not filled up 

 with cement. There are a greater number of grinders simultaneously 

 in each jaw, than in the Elephant ; and although the succession of the 

 back grinders is antero-posterior as in the latter, the first and second 

 molars, both in the upper and lower jaw, are replaced in a vertical 

 direction by a tooth of a simpler form than the second molar. 



A still more remarkable peculiarity is the existence in the lower jaw 

 in the young Mastodon, of two small, short, straight tusks, that project 

 from the anterior extremity ; and these disappear as the animal advances 

 to maturity, except in the tusks of some adult male species, in which 

 one or both are retained. 



But there are transitional forms of Mastodons from Ava, described by 

 the late Mr. Clift, in which the characters of the molars are intermediate, 

 as indicated by the name M. elephantoides ; and Dr. Falconer affirms 

 that the presumed distinctive characters are far from being absolute, for 

 premolars are developed in greater number in one typical fossil species 

 of Elephant than in any known Mastodon ; and though the inferior 

 tusks have been detected in three species of Mastodon, there are other 

 forms in which, even in the young state, no traces of such dental organs 

 are perceptible. 



Lower Jaw of Mastodon with Tusk. On the middle shelf of Wall-case 

 B, in the fifth division of the cabinet, reckoning from the west end of 

 the room, there is a remarkably fine and instructive specimen of a 

 lower jaw of Mastodon Ohiolicus, in which a tusk is seen retained in 

 the socket of the right side. This jaw has on each side three molar 

 teeth, the crowns of which are but slightly worn ; and the root of the 

 tusk is distinctly exposed in consequence of the mesial aspect of the 

 socket having been broken away. 



CHAPTER VI. PART III. 

 MASTODONS AND ELEPHANTS OF NORTH AMERICA. 



SKELETON OF THE MASTODON OP TEE OHIO (Mastodon Ohioticus) 

 Room VI. I. This fine skeleton was purchased by the Trustees, of the 

 British Museum, of Albert Koch, a well-known collector of fossil 

 remains, who had exhibited in the Egyptian Hall in Piccadilly, under 

 the name of the " Missourium, or Leviathan of the Missouri," an 

 enormous osteological monster, constructed of the bones of this skeleton, 

 together with many belonging to other individuals, the tusks being 

 fixed in their Rockets so as to curve outwards on each side of the head. 

 From this heterogeneous assemblage of bones, those belonging to 

 the same animal were selected, and are articulated in their natural 



