64 
LOWER MAMMAL OALLERY. 
[Central 
Hall & 
Geol. 
DeptC 
The molars resemble those of Rhinoceroses, but the incisors 
are unique in structure and shape, the upper ones being typi- 
cally rootless and triangular in section, with one of the angles 
Fig-. 36. 
directed forwards, so that, by a mode of wearing somewhat 
similar to that descril)ed in Rodents, a sharp point is formed 
and preserved at this angle. The lower incisors are short, 
flattened, and rooted. The dental formula is : — I. j, C. 
Pm. I, M. f x2 = 34. 
Suborder Proboscidea. 
This suborder, so named from the long trunk or proboscis 
into which the nose and upper lip are produced, consists, at 
the present day, of two species only, the African and Indian 
Elephants ; but these are survivors of a number of extinct 
species which ranged in former times over the greater part of 
the Old and New Worlds. 
Elephants are heavily-built animals, with large ears, nostrils 
produced into a long flexible trunk, thick limbs, each provided 
with five toes enclosed in a common skin, so that only the nails 
show externally, a w^ell-developed tail reaching nearly to the 
ground ; and the skin almost naked, although in the extinct 
Mammoth clothed with long shaggy hair. The upper incisor 
teeth grow into long curved tusks, directed downward and 
forward (fig. 37). 
