250 BELLU^. 



Synopsis of Suborders and Families. 



Section I. ORTHOGNATHA. The jaws of the usual shape, the 

 dental edge nearly straight ; the three kinds of teeth of the 

 usual form and shape. Teats abdominal or inguinal. 



Subsection 1. Skull and jaws tapering in front; nostrils termi- 

 nal ; eyes lateral. Terrestrial animals. 



Suborder 1. Nasuta. Nose produced into a short proboscis. 



Toes 3 . 3 or 4 . 4 ; hoof subtriangular. 

 Fam. Tapieid^. 

 Suborder 2. Solidun^ula. Nose rounded, soft, simple ; upper 



lip prehensile. Toes 2, united and enclosed in a single 



lunate hoof; lateral toes none. 



Fam. Equid^. 



Suborder 3. Laminiuigula. Nose rounded, simple ; upper lip 

 prehensile. Toes elongate, separate, applied to the 

 ground the greater part of the length ; hoof small, 

 nail-like. 



Fam. Htracid^. 



Suborder 4. Nasicornia. Nose rounded, with one or more 

 central horns of agglutinated bail' ; upper lip prehensile. 

 Toes 3 . 3, rudimentary and reaching the ground ; hoof 

 nail-like. 



Fam. RniNOCEKOTiDiE. 

 Suborder 5. Setifera. Nose truncated, with a bony button on 

 the edge. Toes 4, triangular ; hoofs in pairs, hinder 

 pair not reaching the ground. 



* Pre}nolars permanent, forming one series loiih the molars. 



Fam. Sthd^. Teeth 40 or 44. Toes 4 . 4, outer hinder 

 as long as the other. Tail thin. 



Fam. DicoTTiiD^. Teeth 38. Toes 4 . 3, the outer hinder 

 toe wanting. Tail none. 



** Premolars deciduous, their 2}lctce ocetipied hy the development of the 

 molars. 



Fam. Phacochcerid^. Toes 4 . 4, hinder ones small. Molars 

 very large. 



Subsection 2. The front of the jaw truncated, very wide and 

 dilated. Nostrils and eyes high up, on a line with the base 

 of the ears. Aquatic. 



Suborder 6. Obesa. 

 Fam. HippopoTAMiD-E. 



Section II. HETEROGNATHA. The front of the jaws contracted, 

 the upper jaw bent down on the non-produced, sloping lower 



