MONOTREMATA. 



473 



grinders, but have no roots. The eyes are small but brilliant, and 

 the orifice of the ear is readily detected by its opening and closing 

 in a living animal, tliough scarcely perceiDtible after death. This 





Fm. 398.— THE DUCK BILL. 



creature is sometmies called the Water-mole. It delights to haunt 

 the broad and tranquil ponds that are formed by the expansion of a 

 stream, in which it swims and dives with great facility. Its 

 burrow is formed in the bank, and runs to a great distance \mder- 

 ground, sometimes extending even fifty feet. A nest of grass and 



K 



^^ ^ 





Bijuuow iiF u^;:^,mloItY^■(,•Hus. 



weeds is formed at the extremity, where the parent rears it young. 

 The Ornythorynehus iiilial)its Austraha, 



_ The Porcupine Ant-ea,ter (Echidna aculeata) is another Austra- 

 lian animal, the muzzle of which forms a beak, but less developed 

 than in the Duck-bill. It is clothed with bristly black hair, among 



