THE REPTILIAN MAMMALS. 



231 



CHAPTER XXXII. 

 THE REPTILIAN MAMMALS. 



BEFORE we come to the true mammals, we should notice 

 two very singular forms which in some important respects 

 are intermediate between the reptiles and birds and the 

 higher mammals. These are the duck-bill and spiny ant- 

 eater. Besides peculiarities in the breastbone and other 

 parts, one of the most obvious distinctions in these animals 

 is the long, toothless jaws (there are eight horny teeth in 



FIG. 233. Duck-bill. Australia. (One-fourth natural size.) 



the duck-bill), which are long and narrow in the Echidna, 

 or broad and flat in the duck-bill (Ornithorhynclnis para- 

 doxus), where it is covered by a leathery integument; the 

 external ear is wanting; in these respects they resemble 

 reptiles and birds. 



In the aquatic duck-bill (Fig. 233) the feet are webbed, 

 with claws of moderate size. It is covered with a soft fur, 

 and is about half a metre (17-22 inches) long. Its habits 



