20 THE COLLECTION OF FOSSIL VERTEBRATES 
Most remarkable among extinct carnivora are the Sabre Tooth 
Tigers, in which the upper canine teeth are enlarged into long, 
curving, flattened, serrate fangs, most terrible weapons, effective 
no doubt against the thick hides of the primitive pachyderms. 
North The fourth alcove is very narrow. In it are placed 
Alcove 4. @ few remains of fossil marine mammals: Seals, Ceta- 
Marine ceans and Sirenians. These groups are very imper- 
Mammals. foctly known as fossils. 
The fossil ELEPHANTS and Mastodons are in the next broad 
North alcove, about the middle of the hall. The evolution of 
Alcove 5. these animals is shown by a series of skulls. The 
Probos- = Mastodon skeleton and the skull and fore-limb of the 
cidee Imperial Mammoth from Texas, and tusk of the Si- 
berian (Hairy) Mammoth are noteworthy specimens. 
Beyond the Elephants are the ArtiopactyLs or Cloven- 
Hoofed Mammals. They divide into two groups, typified by the 
North Pigs and the Ruminants, the latter including the greater 
Alcove 6. part of modern hoofed mammals, but by no means pro- 
Elotheres. ortionally common as fossils. First among the fossil 
artiodactyls are the Elotheres, an extinct race of large animals 
distantly related to Pigs and Hippopotami. Next are the fossil 
Peccaries; then the Oreodonts, pig-like animals with the teeth 
North of ruminants, very abundant in America during the 
Pane 7- middle and later Tertiary, but extinct before the Plio- 
ae cene epoch. Then come the Camels, which although 
Oreodonts, now found only in Asia and South America, originated 
Camels. jin North America, and afterwards migrated to these 
other continents and became extinct in their native land. The 
evolution of these animals is shown by a series of stages only 
less complete than the stages in the evolution of the Horse. 
The higher ruminants (Deer, Antelope, Sheep and Cattle) are 
rather poorly represented in the collections. The Great Irish 
North Deer is the most striking among the extinct species; 
Alcove 8. attention is also called to the mounted skeletons of 
Deer, Ante- Protoceras, a deer-like primitive ruminant of the Oligo- 
lope etc. Gene epoch, and of Merycodus, a graceful little animal 
of the Miocene epoch intermediate between the Deer and the 
Prong-horn Antelope. 
