MAMMALS. 13 



t Anterior and posterior limbs and pelvis well developed ; 

 femur and liumerus 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. . . CARNIVORA, 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. (!NEDUCABILIA.) 



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

 c. Anterior limbs adapted for flight ; ulna and radius 

 united; bones of hand and fingers much elon- 

 gated, supporting a thin, leathery 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; mammae usually abdomi- 

 na l INSECTIVORA, D. 



Vb. 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 

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



A. FAMILIES OF CARNIVORA. 



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



5-4. 

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



retractile FELID.E, 1. 



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

 retractile CANID^, 2. 



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

 toes 5-5. 



