LEPORID^E. 223 



The OcTODONTiN^ have rootless molars, and usnally 5 toes to each foot, 

 with large claws. They have mostly large eai's, and a long or moderate 

 hairy tail. They are of small size, and burrow. Their general aspect is 

 intermediate to that of chinchillas and voles. The chinchillas (Chin- 

 chilling) have rootless molars and stout claws, as the last; but the 

 niTmber of toes is usually less. The tail is moderate and hairy, and held 

 recurved, and the ears are generally conspicuous. The clavicles are 

 developed in this and the last group. The Chinchilla, Chinchilla laniger, 

 whose fur is so highly prized, and the Viscacha, Lagostomvs tricho- 

 dactylus, are the best-known species. They burrow in the ground, and 

 live in numerous societies. The hind-feet are usually considerably 

 larger than the anterior, and the animals hold their food, like the 

 squirrels, between the short fore-paws. All the species of the two last 

 sub-families are exclusively confined to South A.mei'ica. 



Fam. Leporid.^, Hares. 

 Syn. Duplici-dentata, Van der Hoeven. 



Upper incisors 4 in number, there being two thin teeth placed behind 

 the anterior and larger teeth. Molars 5 or 6 on each side above, and 6 

 beneath on each side, rootless, and formed of two laminae joined together 

 by a transverse ridge of enamel. Fore-feet with 5 toes, hind-feet with 4, 

 all with hairy soles ; nails long, compressed ; tail short or none. 



This family is distinguished from all other rodents by the possession of 

 a small additional incisor placed behind each of the large incisive tusks 

 of the upper jaw. These small teeth are considered to be the true incisors, 

 the front teeth being, as before stated, the representatives of the canines. 

 Their orbits communicate with each other through an aperture in the 

 septum, as in birds. They have an enormous csecum lined internally with 

 a spiral layer throughout its entire length. There are only two well- 

 marked generic forms, Lepns and Lagomys. 



Gen. Lepus, Linnaeus. 



o _ 2 3 3 3 3 



Char. — Incisors 1 : prsemolars : molars The last 



1—1 ' ^ 2—2 3—3 



mohir above small and simple ; ears typically very long ; tail short, 



recurved. Hind-legs much longer than the fore-legs. Their clavicles are 



imperfect. 



