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of the black bear ( TJrsus Americanus) ; other species were not 
larger than a fox. These were the last survivors of a group 
notably different from any now existing. 
The remaining American carnivores of the Miocene and 
more recent ages can be, as far as they are known, referred to 
one or other of the groups into which the order is now divided. 
The dog-like forms were abundant throughout the Miocene and 
Pliocene ages. But in the earliest period more generalised 
types were met with, assigned to the well-known European 
genus Amphicyon , which differs from the true dogs in the more 
tuberculated character of its molars, and the presence of the 
last upper tooth of this class, which is missing in the modern 
Canidce , and also in the more bear-like structure of its limbs. 
Various modifications of Felidce were also abundant, the most 
remarkable in the Miocene period belonging to that group 
{Mo, cheer odus or Depranodon ), with immensely developed 
sabre-like upper canine teeth, which flourished throughout such 
an extensive period of time and in so many parts of the world : 
in the sub-Himalayan region ; in Miocene and Pliocene epochs 
in various parts of Europe, and almost down to recent times in 
England, as we know by the teeth found in Kent’s Hole ; in 
South. America, where remains of its largest and most powerful 
form (M. neogeeus) have been found in the caves of Brazil and 
in the alluvial plains of Buenos Ayres ; and again in the 
Miocene of the North American territories. Why this form, 
so highly specialised for its mode of life, once apparently the 
dominating type of the whole order throughout the world, 
should have entirely disappeared, and given way to the more 
modestly armed modern tigers and leopards, is not very easy to 
explain. 
From the time of the extinction of the sabre-toothed cats in 
North America, to the present period, other forms more like 
those now existing continue to prevail, none, however, equalling 
in size those of the Old World lion or tiger; but of the other 
families of the carnivora little has hitherto been found. Ursidce 
and Mustelidce , except in Pleistocene deposits, are very rare ; 
and, what is more remarkable, remains that can with certainty 
be referred to the Procyonidce , a group whose head-quarters are 
in America, have not been met with. The families which were 
previously mentioned as not now existent in that continent are 
equally unknown in its extinct fauna. 
Perhaps the most conspicuous, both on account of their 
colossal size and their singular conformation and habits, of the 
animals inhabiting the American continent in the period imme- 
diately preceding the one in which we now live, were the great 
ground sloths, known to us familiarly by the names of Mega - 
therium , Mylodon , Megalonyx , &c. As these animals are 
