The Mammals of New Jersey. 
Mammals, the majority of which are more popularly known 
as quadrupeds, form the highest class of Vertebrate or “back- 
boned” animals, 
Most of them are four-footed and covered with hair, and are 
terrestrial in their habits, such as the dog, the horse and the 
mouse, but two groups that belong to the mammalia differ ma- 
terially from the rest, both in external appearance and in habit. 
The bats, while looking not unlike mice so far as their head 
and body are concerned, have their hands modified into mem- 
branous wings which are carried down the sides of the body so 
as to include the hind legs and tail, thus, admirably fitting these 
little animals for their aérial life. 
The whales and dolphins, on the other hand, are fitted for a 
life in the ocean. They are practically hairless, with no trace 
of hind limbs, the fore limbs modified into flippers, the tail broad 
and flat like that of a fish, only that it is transverse instead of 
vertical. These beasts look little like the hairy quadrupeds of 
the land, and it is not surprising that in the popular mind they 
are associated with the fish. As a matter of fact their skeletal 
structure is like that of the quadrupeds, while they have warm 
blood and suckle their young, all of which are essential charac- 
teristics of the class of mammals. The existing mammals fall 
into three groups: 
(1) The Prototheria, curious remnants of an earlier fauna, 
now only represented by the Duckbill and Spiny Anteater of 
Australia, mammals with horny bills like birds and which lay eggs 
somewhat like those of certain reptiles. 
(2) The Marsupialia or pouched mammals also an ancient 
group represented by the Kangaroos and other Australian mam- 
mals and by the opossums of North and South America. 
(37) 
