272, PROBOSCIDIA. 
the tropical regions of Asia and Africa; and we have seen 
in the preceding section, that an extinct species of this 
genus once ranged over the whole of the temperate, and 
part of the arctic zones of the northern hemisphere of the 
globe, and has left abundant evidence of its former exist- 
ence in our own island. 
In like manner we learn from the study of fossil re- 
mains, that other quadrupeds, as gigantic as Elephants, 
armed with two as enormous tusks projecting from the 
upper Jaw, and provided with a proboscis, once trod the 
earth; the presence of the latter flexible organ being 
inferred, not only by its necessary coexistence with long 
tusks, which must have prevented the mouth reaching the 
ground, but also by the configuration of the skull, by the 
holes which gave passage to large nerves, and by depressions 
for the attachment of particular muscles, analogous to those 
which relate exclusively to the organization of the trunk in 
the Elephant. Like the Elephants, also, these other huge 
proboscidian quadrupeds were destitute of canine teeth, 
and provided with a small number of large and complex 
molar teeth, successively developed from before backwards 
in the jaws, with a progressive increase of size and com- 
plexity, from the first to the last. The broad crowns 
of the molar teeth were also cleft by transverse fis- 
sures; but these clefts were fewer in number, of less 
depth, and greater width than in the Elephants: the 
transverse ridges were more or less deeply bisected, and 
the divisions more or less produced in the form of udder- 
shaped cones, whence the name Mastodon,* assigned by 
Cuvier to the great proboscidian quadrupeds with teeth 
of this kind. 
A more important difference presents itself when the 
* Etym. Gr. mastos, udder, odos, a tooth. 
