CHORD ATA — VERTEBRATA — MAMMALS 379 



Order j, Insectivora 



Small mammals, eating worms and insects, — (whence the 

 name) . 



These have a low type of brain and occur from the Jurassic 

 to the present, including the extinct sub-order of the Jurassic 

 Pantotheria. The living families of the moles, shrews and hedge- 

 hogs have existed since the Eocene. 



Order 4, Chlroptera {Bats) 



Mammals with the fore limbs modified to form wings by the 

 development of a broad web between the greatly elongated 

 fingers (usually the second to fifth) and the sides of the body 

 and the hind Hmbs (hence the name from Greek cheir, a hand, 

 + pteron, a wing). Breastbone with a keel for attachment of 

 flying muscles. 



This trder is kntfwn from the basal Etc^ie of C#l#rad#- to the 

 present, and n#w includes the fruit-eating bats ff the tr-#pics 

 of the Eastern Hemisphere and the insect-eating bats so abun- 

 dant throughout the world. 



Order 5, Carnivora {Cats, Dogs, etc.) 



Fur-covered, flesh-eating mammals (whence the name from 

 Latin carnis, flesh, + vorare, to devour) ; all teeth have cutting 

 edges. 



This order is known from the Eocene to the present. It 

 includes: (i) the extinct primitive Creodonta (Basal Eocene to 

 Lower Oligocene, mostly of North America, but also of Europe 

 and Africa). These are such generalized types that they are 

 only with difficulty distinguished from the Eocene Insectivora 

 and Ungulata. As they do not possess well-developed sectorial 

 teeth (see below under Fissipedia), they are not perfected as 

 flesh eaters. Examples of these are Mesonyx and Patriofelis 

 (Fig. 163, 2-4), both from the Middle Eocene (Bridger) of the 



