XVI I.STRODDCTION 



III. IsoDONTiA. — Teeth wlien present of one kind and often 



■very numerous. 

 Ord. Cetacea. — Post-extremities wanting. 



B. IMPLACENTAL OR MARSUPIAL MAMMALS. 



In the body of the work the orders do not follow exactly as in 

 this synopsis. I have made the Insectivora follow the Bats, and 

 the Cetacea the Carnivora. 



This classification is nearly that of Cuvier, but he classed Bats, 

 Insectivora and Carnivora in one group, Carnaria, and placed the 

 Sirens with the true Cetacea. 



The following is the classification adopted by Linnseus, 



I. Ukgoiculata. — With nails. 

 Ord. Primates. — Monkeys and Bats, 

 „ Fe?-m. — Insectivora and Carnivora. 

 „ GUres. — Are Rodentia. 

 „ Bruta. — The Ant-eaters, Elephant and Rhinoceros. 



II. Ungulata. — Hoofed. 

 Ord. Pecora. — Ruminantia. 



Bellua. — Pachydermata, except the order Bruta above. 



III. MuTiCA. — Wanting the posterior extremities, Cetacea. 



This it will be seen is, with the exception of his separating the 

 Elephant and Rhinoceros from the other Bachydermata, essentially 

 the same as Cuvier's, and the system adopted here. 



Professor Owen classifies Mammals according to the structure 

 of the brain alone, and, excluding Man, whom he places by himself, 

 as the type of his Archencephala, he divides the Mammal class into 

 three great groups — Lyencephala, Lissencephala, and Gyrencephala. 

 The first comprises the Implacental or Marsupial animals, and is 

 quite natural. In this group the olefactory lobes, part of the optic 

 lobes, as well as the cerebellum, are all exposed, and the lobes of 

 of the cerebrum are not connected by a corpus callosum. 



The Lissencepballa, or smooth-brained Mammals, have the carpus 

 callosum, but the cerebrum is smooth in most and of small bulk. 

 This group is composed of the Clieiropteraf Insectivora, Bodentia and 



