DISTRIBUTION OF OPHIDIANS. 
239 
deep forests, and of immense extent, as Brazil, there should 
exist only a single species of Squirrel, the Sciurus sestuans : 
this fact is the more remarkable, because we observe a 
great number of reptiles that constantly live on trees, as 
the Tree Frogs, the Leguans, the Anolius, &c. ; and be- 
cause there exist several species of squirrel in North Ame- 
rica.^ South America produces a very considerable 
number of aquatic animals, especially in the class of 
reptiles ; but it is a very remarkable fact, that among the 
great number of fresh- water Tortoises, there is but one 
species of Trionyx, which is called by way of eminence 
the Water Tortoise^ and of which one species is found in 
North America. As regards the large mammifera, those 
of North America are almost all different from those of 
the southern peninsula of the New World, and often have 
a great affinity to those of Europe, belonging ordinarily 
to the same genera. We find there, for example, two 
species of Bos ; one, the Bison, appears very near the 
Ursus or European Bison ; Elks and Beindeer are also 
found there, different, as it seems, from those of Europe ; 
the Wolves, Canis nubilus and C. latrans, probably 
only form local varieties of those of Europe : the North 
American Beaver, on the other hand, has specific differ- 
ences from ours ; of the three Bears inhabiting America, 
two, Ursus ferox, and U. Americanus, are peculiar to 
that peninsula ; the third is the same as the European 
species. We there find a great number of the family of 
Spermophili, some of which are very like the species of 
Europe and Asia. The Marmottes, the common Fox, the 
common Lynx, and the Glutton of North America, do not 
differ from those of Europe ; but the Badger of Labrador 
is very different from ours. The Scalops and the Condy- 
lurus there represent our Moles and Musk Bats. The lofty 
mountains stretching along the western coasts of North 
* One species of that country, the Sciurus Capistratus or S. Caro- 
linensis is very remarkable for the numerous varieties which it forms : 
they are white, black, grey, brown, in short, of all colours. The species 
appears to inhabit even Mexico : compare them with Sciurus hypo- 
xanthos of Lichtenstein. 
