SURVEY OF THE ORDERS OF MAMMALIA 833 



4. Ungulata. 



Artiodactyla. 1 ^t 1 x -.r 

 r, ■ ^ 4. 1 Ungulata Vera. 

 Penssodactyla. j ^ 



Hyracoidea. 



Proboscidea. 



Extinct sub-orders. 



5. Cetacea. 



Mystacoceti — baleen cetaceans. 

 Archaeoceti — (extinct types). 

 Odontoceti — toothed cetaceans. 



6. Rodentia 



Simplicidentata. 

 Duplicidentata. 



7. Carnivora. 



8. Pinnipedia 



9. Insectivora. 



10. Chiroptera. 



Megachiroptera. 

 Microchiroptera. 



11. Prosimiae or Lemuroidea.) t^ . 



. , . , } = Primates. 



12. Anthropoidea. J 



Sub-Class Prototheria (Syn. Ornithodelphia), 

 Orders Monotremata and (?) Allotheria 



The Monotremes include the duckmole (Ornithorhynchus 

 afiatinus), the spiny ant-eater {Echidna aculeata), and a 

 third form resembling Echidna^ but often referred to a 

 distinct genus as Proechidna. These are the lowest 

 Mammals, very different from all the rest, and they exhibit 

 affinities with Reptiles. 



The duckmole is found in the rivers of Australia and 

 Tasmania ; Echidna in Australia, Tasmania, and New 

 Guinea ; Proechidna in New Guinea. 



In Ornithorhynchus the skin is covered with soft fur ; in 

 Echidna and Proechidna there are spines among the hairs. 

 The mammary glands in the female Ornithorhynchus open 

 on a flat patch ; in Echidna, in a depressed area around 

 which a temporary pouch seems to be developed. There 

 are no distinct mammae. 



53 



