MASTODON 



355 



are soon shed in the female, but one of them is retained by the 

 male (fig. 112, B). The upper tusks are long and retained in 

 both sexes (fig. 112, A).* 



An almost entire skeleton of a Mastodon {M. turicencis) 

 has been discovered in the pliocene deposits of Aste\ Pied- 

 mont, and has been described and figured by Professor Sis- 

 monda,t from whose beautiful Memoir fig. 112 is taken. The 

 total length from the tail to the end of the tusks is 17 feet. 

 The teeth have the same narrow shape and multi-mammillate 

 structure as in M. o r ccmensis, but in the numerical character 

 of transverse divisions of the crown this species agrees with 

 M. Ohioticus. 



The Mastodons were elephants with the grinding teeth 

 less complex in structure, and adapted for bruising coarser 

 vegetable substances. The grinding surface of the molars 

 (fig. 113), instead of being cleft into numerous thin plates, 

 was divided into wedge-shaped transverse ridges, and the 

 summits of these were subdivided into smaller cones, more 

 or less resembling the teats of a cow, whence the generic 

 name.J A more important modification appeared to distin- 

 guish the extinct 

 genus, in respect of 

 the structure of the 

 molar teeth ; the 

 dentine, or princi- 

 pal substance of the 

 crown of the tooth 

 (fig. 113, d) is cover- 

 ed by a thick coat 

 of dense and brittle 

 enamel (e) ; a thin coat of cement is continued from the 



d 



Fig. 113. 

 Upper molar of Mastodon. 



* Owen's " Odontography," p. 618. 



f Osteograna di un Mastodonte augnstidente, 4to, 1851. 



\ /uckttoj, a nipple ; oSovs, a tooth. 



