IA4 The Official Guide to the 
cHID#, the Duck-bill, and (2) Ecuipnipa, the Spiny 
Ant-eater. ‘These two families—between which there 
are no known extinct intermediate forms, and which 
although agreeing in many important characters, differ 
very considerably in others—it is still thought desir- 
able by the authorities just named to retain in one 
order. : 
The sub-class, METATHERIA, too, contains but 
one order, that of MARSUPIALIA, the pouched 
animals, Opossums, Wombats, Kangaroos, etc. 
The third sub-class, LUTHERIA, PLACENTALIA, 
r MONODELPHIA, is a very comprehensive one, 
consisting of nine orders and many sub-orders and 
families. ‘The orders are as follows, (1) EDENTATA, 
the Sloths, Ant-eaters, etc.; (2) SIREN IA, Manatees 
and Duzone ; (3) CETACEA, Whales ; (4) UNGU- 
LATA, hoofed animals; (5) RODENTIA, gnawing 
animals; (6) CARNIVORA, flesh-eating animals ; 
(7) INSECTIVORA, Shrews, Moles, Hedgehogs ; 
(8) CHIROPTERA, Bats, Flying Foxes; and (9) 
PRIMATES, Lemurs, Monkeys, Man. 
Of the remarkable forms constituting the two 
families of the Order MONOTREMATA (so called 
from its members possessing a single excretory 
passage), we have good examples; they are all 
confined to the Australian region. The single mem- 
ber of the first family is the DUCK-BILLED PLATYPUS 
(Oruithorhynchus canaiinus), or as it is sometimes 
called by the colonisis, the Water-Mole, although of 
course it has no affinity with the latter animal, its 
nearest relatives perhaps being the Amphibia. The 
female Duck-bill lays two white eggs about three- 
quarters of an inch in their lon-est diameter, and 
the young ones are subsequently nourished with 
their mother’s milk. The food of, these animals 
consists of aquatic insects, worms, and crustaceans, _ 
