INTRODUCTION. XV 



minal pouches, and a general similarity of organization ; some 

 of them, however, in their teeth and the nature of their diet, 

 correspond to the CARNARIA, others to the RODENTIA, 

 and a third to the EDENTATA. 



VII. RUMINANTIA, with cloven feet 5 no true incisors in 

 their upper jaw j and with four stomachs. 



VIII. PACHYDERMATA, containing all the remaining 

 hoofed animals, and most of them remarkable for the thickness 

 of their hides. 



IX. CETACEA, without posterior extremities, have a fish- 

 like form, but resemble the other mammals in their economy, 

 are aquatic, and are also the most gigantic of animals. 

 To this order belong the whale, manati, rorqual, cachalot, 

 narwhal, bottle-head, porpoise, grampus, and dolphin, which 

 were formerly classed among fishes. Man and these animals, 

 that is to say, the first and last orders, will not be treated 

 of here, but only those mammals which are four-footed. 



