230 ANIMAL FORMS 
country. Of the other three the first (Monotremes) and 
simplest of the eleven is represented by the duck-mole 
Fig. 130.—Australian duck-mole (Ornithorhynchus paradoxus). One-fifth natural 
size, 
(Ornithorhynchus) living in the Australian rivers. Its 
general appearance and mode of life are represented in 
