8 Mam. Classification. 



sometimes two, e.g. Camelopardalis Giraffa ; and sometimes 

 two functional and two rudimental, e.g. most Rmninantia. If 

 the species be horned, the horns form one pair or two pairs ; 

 they are never developed singly, nor if there be two are they 

 placed on the median line of the head. 



The Order Artiodactyla readily divides into two 



Sub-orders : 



1. OmXIVORA- 2. RUMIXANTIA. 



The Sub-order Omxivora comprehends those species which 

 Cuvier grouped together as the " even- toed Pachydermata 

 Ordinaria," and of which he said, that they approximated 

 the Ruminants in various parts of their skeleton, and even 

 in the complication of the stomach, viz. the 



Two Families 

 of the Hippopotamidce and the Suidcp. Of these the species 

 of the former have four toes, each terminated by a hoof to 

 each foot ; while the species of the latter have two hoofed 

 toes functional, i.e. available for walking, and twof others, 

 rudimental, placed at some little elevation on the back of the 

 foot. 



2. The Sub-order Ruminantia (the Pecora of Linnaeus, 

 and recognised by Aristotle as a natural Order, under the 

 title fivpnica^oyra) , is one of the most distinctly circumscribed 

 groups of Mammalia ; one family alone, the Camelidac, pre- 

 senting any considerable exceptions to the general characters 

 of the Sub-order ; such as are, the absence f of incisors in the 

 upper jaw, and their replacement by a callous pad ; the 

 likeness and approximation of the lower canines to the lower 

 incisors ; the wide diastema anterior to the molar series ; 

 the true molars marked as to their crowns with two double 



* In Dicotyles tlie hind feet are said to have only three toes, one of the 

 hinder ones being deficient. 



t The Camelidce have a single pair of incisors in the upper jaw ; and lower 

 canines, and incisors dissimilar. 



