298 BACKBONED ANIMALS. 
Spiny Ant-eaters (Zc/idnide).—These animals (Fig. 
322, A) are covered with spines like the hedgehog ; the 
bill is long, horny, and toothless, resembling that of a bird. 
The tongue is long, like that of the ant-eater, and the pal- 
ate armed with rows of sharp, tooth-like spines. Their 
claws are powerful and adapted for digging into the ant- 
hills where their food is obtained. They produce a single 
egg at a birth, that is carried in a ventral pouch. 
= 
Fic. 322.—Group of egg-laying mammals. .4, Echidna; 2, Ornithorhyn- 
chus swimming and rolled up; C, nest of duck-bill in section. 
Duck-bill (Ornithorhynchide).—The water mole (Fig. 
322, B), as it is sometimes called, has a broad, duck-like, 
horny bill (Fig. 323, 4), containing eight broad, flat, horny 
teeth. They have no external ear. The body is covered 
with short, brown hair with an under-pelt ; the fore-feet 
are webbed (Fig. 323, C) beyond the claws, the hinder 
only to their base, the males possessing a bird-like spur 
