Mammalia: Classification 747 



and five on the pes, bear heavy blunt claws, but the plantigrade feet 

 are not highly specialized for digging. It is described, however, as 

 burrowing and nocturnal in habit. 



The name of the Order refers to a peculiarity of the teeth. The 

 dentition consists of four or five cylindric cheek-teeth in each half-jaw. 

 They lack enamel. The dentine of the crown of the tooth consists of 

 numerous tubular columns extending parallel to the axis of the tooth 

 and each traversed by a canal which connects with a common pulp- 

 cavity in the base of the tooth. 



Order 12: CARNIVORA. Aside from the teeth, most of these 



mammals are devoid of peculiarly specialized anatomic features. They 



are mainly, but not exclusively, flesh eaters. Dentition complete and 



strongly heterodont (Figs. 136, 165): incisors small, sharp-edged; 



canines long, conical, sharp-pointed, in some cases exaggerated into 



tusks (eg., walrus and extinct "saber-tooth" tiger); cheek-teeth 



shaped for cutting, each bearing several cusps with sharp edges and 



3 14 2 . . 

 points. Dental formula for dog, i ^> c y> p^> m ^- Digits usually five, 



never fewer than four, bearing sharp claws which may be retractile 

 (as in the cat). Stomach simple. Brain well developed; the cerebral 

 hemispheres strongly convoluted. 



The great majority of carnivores are terrestrial, but a few have 

 become highly adapted to aquatic life. Hence the two Suborders: 



Suborder FISSIPEDIA (CARNIVORA VERA). Terrestrial 

 or, in a few cases (e.g., otters), semiaquatic. Seven Families are 

 recognized: 



Canidae: Dog (Canis), wolf, fox. 



Procyonidae: Raccoon (Procyon), South American kinkajou, 

 Asiatic panda (Fig. 557). 



Ursidae: Bears (Ursus). 



Mustelidae: Weasel, ermine, ferret, marten, mink (all in 

 Genus Mustela); skunk (Mephitis) ; otter (Lutra) : (Figs. 558, 603). 



Viverridae: Civet (Viverra); mongoose (Herpestes); genet 

 (Genetta: Fig. 559). In Eastern Hemisphere only. 



Hyaenidae: Hyenas of Asia and Africa. 



Felidae: Cat, lynx, jaguar, lion, tiger, leopard, panther 

 (all in Genus Felis) : (Fig. 560). 



Suborder PINNIPEDIA. Aquatic. Body streamlined, approach- 

 ing fishlike form; short tail, no tail-fin. Pectoral and pelvic limbs well 

 developed, but short and externally finlike ("flippers"), the five digits 

 being webbed together. Three Families are recognized: 



Otariidae: "Eared seals, " having small pinnae; pelvic flippers 

 can assist in clumsy locomotion on land. Sea lion, fur seal (Fig. 561). 



