XX V] CLASSIFICATION 723 



Family 2. Proboscideae. 



Large Sub-unguiata with a very long flexible snout 

 (trunk) used for prehension:' incisors long and curved, 

 forming tusks : molars very broad, only one pair in use at 

 a time. 



Ex. Elephas. 

 Sub-order 2. Ungulata vera. 



Ungulata in which the bones of the carpus and tarsus are 

 arranged in transverse rows, the members of successive rows 

 alternating with one another. The first digit is lost. 



DIVISION I. PERISSODACTYLA. 



Ungulata in which there is, with rare exceptions, an un- 

 even number of digits in each limb, and in whichjfche axis of 

 symmetry passes through the third digit. 



Family 1. Tapiridae. 



Perissodactyla with four digits in the fore-limb and three 

 in the hind-limb : a short flexible snout. 



Ex. Tapirus, 

 Family 2. Rhinocerotidae. 



Perissodactyla with three subequal digits in each limb : 

 one or two median horns without bony cores carried on the 

 nasal bones. 



Ex. Rhinoceros. 

 Family 3. Equidae. 



Perissodactyla with only one complete digit in both 

 fore- and hind-limbs. 

 Ex. Equus. 



DIVISION II. ARTIODACTYLA. 



Ungulata in which there is almost always an even number 

 of digits, and in which the axis of symmetry passes between 

 the third and fourth digits, these digits being flattened against 

 each other so as to form two symmetrical halves of a cylinder. 



Section A. Bunodontia (Suina). 



Artiodactyla with comparatively simple stomachs : the cusps 

 on the molar teeth are separate. 

 Family 1. Hippopotamidae. 



Large Bunodontia with four subequal toes in both fore- 

 and hind-limbs. 



Ex. Hippopotamus. 



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