MAMMOTHS AND MASTODONS. 253 



series, we should have a succession somewhat as follows : 

 (1) Mastodon angustidens; (2) Mastodon latidens; (3) Mas- 

 todon elephantoides ; (4) Elephas planifrons ; (5) Elephas 

 Africa HKS; (6) Elephas Hysudricus; (7) Elephas Indicus. 

 This at least represents the order of divergence of the 

 molar from the mastodont type, and this is the historical 

 order of existence of the species now extinct. The Afri- 

 can elephant thus seems to be a survivor of times as re- 

 mote as those in which the Hysudric elephant flourished, 

 and its remains have been actually discovered in the 

 Newer Pliocene deposits of the island of Sicily, in associ- 

 ation with those of another elephant (Elephas antiquus), 

 which came down from the preceding epoch. Here we 

 have a successional order and a parallel structural rela- 

 tionship exactly like those which have been traced in the 

 geological history of the horse-type, though not by any 

 means extending -over a geological interval of equal length. 

 The mastodon preceded the elephant in both the Old 

 World and the New; and this is in accordance with their 

 respective degrees of divergence from still older mammals. 

 In North America the mastodon is known both in the 

 Older and Newer Pliocene. In Europe it made its first 

 appearance at an epoch generally placed, but perhaps 

 erroneously, a little earlier, Mastodon lonyirostris and Mas- 

 todon tapiroides being referred to the Miocene or Middle 

 Tertiary. As the mastodon, on the one side, graduates 

 into the succession of elephants, on the other, one of the 

 oldest mastodons of Europe (M. tapiroides) reveals affini- 

 ties with the more ancient types of tapir and dinotherinm ; 

 and the oldest mastodons of America were associated with, 

 or immediately preceded by, other enormous, many-hoofed 

 quadrupeds, so far resembling the mastodon that author!- 



