MAMMALS. 13 



\ Anterior and posterior limbs and pelvis well developed ; 

 femur and kumerus not exserted beyond the common 

 integuments of the body. 



a. Feet with developed claws; canines specialized; molars, 



one or more, sectorial, adapted for cutting ; incisors 



f; chiefly carnivorous. . . CARXIVORA, A. 



aa. Feet with hoofs; molars mostly with grinding surfaces; 



incisors various; no tusks; developed toes, four or 



fewer ; chiefly herbivorous. . . UNGULATA, B. 



ff Brain with a relatively small cerebrum, leaving behind much 



of the cerebellum exposed, and, in front, much of the 



olfactory lobes. (!XEDUCABILIA.) 



/>. Canine teeth present, in some form ; incisors not f nor f . 

 <. Anterior limbs adapted for flight; ulna and radius 

 united; bones of hand and fingers much elon- 

 gated, supporting a thin, leather}' skin, extending 

 along sides of body to the posterior limbs; 

 mammae pectoral. . . CHIROPTERA, C. 

 cc. Limbs all adapted for walking ; ulna and radius not 

 united; hand normal; mamma usually abdomi- 

 nal IXSECTIVORA, D. 



bb. No canine teeth ; incisors f , rarely f, chisel shaped ; 

 limbs adapted for walking. . RODENTIA, E. 



** Young born when of very small size and incomplete develop- 

 ment, never connected by a placenta to the mother; corpus 

 callosum rudimentary. (DIDELPHIA.) . MARSUPIALIA, F. 



A. FAMILIES OF CARNIYORA. 



* Intestinal canal provided with a coecuni ; feet digitigrade; toes 



5-4. 

 f Teeth 28 to 30 ; head broad ; snout short ; claws sharp, 



retractile. . FELID.E, 1. 



ft Teeth 38 to 46; snout elongated; claws bluntish, non- 

 retractile CANID.E. 0. 



** Intestinal canal without a ccecum; feet plantigrade, or, if not, 

 toes 5-5. 



