556 MANUAL OF ZOOLOGY. 



species (O. paradoxus), and the other by two species (E. 

 hystrix and E. setosa). All are exclusively confined to Aus- 

 tralia and Tasmania. 



The Ornithorhynchus or Duck-mole is one of the most 

 extraordinary of Mammals. The body (fig. 236) resembles that 

 of a mole or small otter, and is covered with a close, short, 

 brown fur. The tail is broad and flattened. The jaws are 

 produced to form a beak just like that of a duck in appearance ; 

 hence the name of " Duck-billed animal," often applied to it. 

 The margins of the jaw are sheathed with horn, and furnished 

 with transverse horny plates ; but there are no teeth. The 

 sternum is of five pieces, not counting in the episternum, and 

 there are sternal ribs. The nostrils are placed at the apex of 

 the upper mandible. The legs are short, and the feet have 

 five toes each, furnished with strong claws, which enable the 

 animal to burrow with facility. The toes are also united by a 



Fig. 236. Ornithorhynchus paradoxus. 



membrane or web, so that the animal swims with great ease. 

 The Ornithorhynchus is exclusively found in Australia and 

 Tasmania, and inhabits streams and ponds. Its food consists 

 chiefly, if not exclusively, of insects, and the animal makes 

 very extensive burrows on the banks of the rivers which it fre- 

 quents. The young are born quite blind, and nearly naked, 

 and the method in which they obtain milk from the mother is 

 somewhat obscure, as there are no nipples, nor is there any 

 marsupial pouch. It is certain, however, that the beak of the 

 young animal is extremely different from what it is in the adult 

 condition. The young animal is totally hairless, the mandibles 

 are soft and flexible, the tongue is not placed far back in the 

 mouth (as it is in the adult), and the eye is at first covered by 

 the skin. 



The genus Echidna is represented by two species, E. hystrix 

 and E. setosa, both belonging to the Australian province. The 



