658 MANUAL OF ZOOLOGY. 



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 are fur- 

 nished with transverse horny plates, two in each jaw (fig. 357, 

 B and C) : but there are no true teeth. The sternum (fig. 

 357, D) is of five pieces, 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 membrane or web, so that the 

 animal swims with great ease. The Ornithorhynchus is ex- 

 clusively found in Australia, ranging as far north as Queens- 

 land, and inhabits streams and ponds. Its food consists 

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

 very extensive burrows in the banks of the rivers which it 

 frequents. 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 (Tachyglossus] is represented by four 

 species viz. , E. hystrix, E. setosa, E. Lawesi, and E. Bruijnii, 

 the first being Australian, and the second Tasmanian, whilst 

 the two last occur in New Guinea. The Echidna hystrix is 

 the best-known species, and in some external respects is not 

 unlike a large hedgehog, having the back covered with strong 

 spines, interspersed with a general coating of bristly hairs. 

 The snout has not the form of a duck's bill, as in the Ornitho- 

 rhynchus, but the two jaws are greatly elongated, and are en- 

 closed in a continuous skin till close upon their extremities, 

 where there is a small aperture for the protrusion of a very 

 long and flexible tongue. The jaws (fig. 357, A) are wholly 

 devoid of teeth or anything in the place of teeth ; and the 

 nostrils are placed at the extremity of the cylindrical snout. 

 The feet have five toes each, furnished with strong curved 

 digging-claws, but the toes are not webbed. There are no 

 nipples, but the ducts of the mammary glands open at the 

 bottom of two integumentary pouches, which are said to be 

 sufficiently capacious to hold the young when first born. The 

 Echidna hystrix measures from fifteen to eighteen inches in 

 length, and is a nocturnal animal. It lives in burrows and 



