8 ELEMENTS OF MAMMALIAN ANATOMY 



extinct forms are omitted from this list. The 

 modern orders are as follows: 



6. Arliodaclyla. — Even-toed ungulates (pigs, 

 camels, deer, sheep and oxen). 



7. Pcrissodactyla. — Odd-toed ungulates (tapirs, 

 horses, and rhinoceroses). 



8. Prohoscidea. — Mastodons and elephants. 



9. Sirenia. — Aquatic modifications of the Un- 

 gulata (sea cows and dugongs). 



10. Hydracoidea. — (Conies). Rock and tree-liv- 

 ing ungulates. Oligocene to present. Syria 

 and Africa. 

 (D) Cetacea. — Whales and Dolphins. Eocene to pres- 

 ent. 



A glance at the above outline shows that the class Mammalia 

 is divided into two subclasses, Prototheria and Eutheria; the 

 latter of which include the Didelphia and the Monodelphia. 

 The Monodelphia, or placental mammals, includes four cohorts; 

 mammals with claws, mammals with nails, mammals with 

 hoofs, and aquatic mammals. The Cat belongs to the unguicu- 

 lates and to the order Carnivora, or flesh-eaters. There are 

 two suborders of modern carnivores, the Fissipedia, or terres- 

 trial forms, and the Pinnipedia, or aquatic forms. There are 

 eight families in the suborder Fissipedia, of which the Canidae 

 (dogs), Ursida? (bears), and Felidae (cats) are the most fre- 

 quently seen in America. The family Felidae is represented by 

 only two living genera, Cynaclurus and Felis. The genus Felis 

 includes several species, of which Felis leo (the lion) , Felis tigris 

 (the tiger), and Felis domestica (the cat) are the most familiar. 

 Of the last species, there are several varieties, such as Maltese, 

 Angora, and Manx cats. 



Linnaeus, born in Sweden, 1707, invented the system of bi- 

 nomial nomenclature in accordance with which the scientific 

 name of every plant and animal is composed of two parts, the 

 generic and specific. Thus the house cat is designated Felis 



