526 MAMMALIA. 



otters and moles {Oniithorhynchus, Fig 274:) ; in fact Orni- 

 thorhynchus received the appropriate name of " watermole " 

 from the AustraHan settlers. Echidna is covered with strong 

 spines, and possesses an elongated edentulous snout, with a 

 vermiform protrusible tongue. The short five-toed legs end 

 with powerful scratching claws, which are adapted for rapid 

 burrowing. Ornithorhynchus, on the contrary, has a close soft 

 fur, a flattened body and. as in the beavers, a flat tail. The 



Fig. 273. — EchidtM hystrix. 



jaws, like the beak of a duck, are adapted for burrowing in mud, 

 but are covered by a soft integument which projects at the 

 base of the beak so as to form a kind of shield. The legs are 

 short, with five toes furnished with strong claws and very exten- 

 sible webs : they are equally well adapted for swimming and 

 burro wins;. 



Fig. 274. — Ornithorltynchus paradoxus. 



They lay eggs, with a white membranous shell ; Echidna 

 deposits them in its pouch : and OrniihGrhynchus, which 

 has no pouch, is believed, though this has not been absolutely 

 proved, to lay them in its nest. 



That the Monotremata are oviparous was suggested soon 

 after their discovery, and has been asserted several times since 

 (on one occasion with good reason), but the best authorities 

 regarded them as viviparous, or at least ovoviviparous, until 

 Caldwell in 1884 definitely settled the matter in the case of 

 Echidna by obtaining a specimen with an egg in the pouch. 

 He also found the eggshells of Ornithorhynchus in the nest. 



