53 
MAMMALIA ROOM.] NATURAL HISTORY. 
Gray, from the Cape of Good Hope. The Tetrapturi 
differ from the Common Sword Fish ( Xiphias) by having 
ventral fins, and two small crests, parallel to one another, 
on each side of the tail; whilst the Xiphiae have no ventral 
fin, and only one caudal crest. 
Over the door is a specimen of the Pirarucu (Sudis 
gigas, Cuv.), from the rivers of British Guiana. 
MAMMALIA ROOM. 
This and the adjoining Saloon, which is now under¬ 
going repair for their reception, are to contain the Col¬ 
lection of Beasts or Mammalia, which may be charac¬ 
terized as warm-blooded viviparous animals, covered with 
hair, the females having peculiar organs which secrete 
milk for the nourishment of their young. 
This class is divided into five orders, according to 
the forms of their teeth and modifications of their 
members, which are adapted for their different modes of 
life, and the kind of nourishment they are destined to 
subsist on : some being in the form of hands, others hav¬ 
ing clawed or hoofed feet for walking, or fin-like paddles 
for moving in the water. 
The first order of Mammalia, called Primates, be¬ 
cause they are considered as the most perfect animals, 
is placed in this room. They are characterized by having 
distinct and well defined cutting, canine and grinding 
teeth, placed in a regular uninterrupted series. The front, 
and most generally the hinder extremities, are in the shape 
of a hand, having the thumb placed lower down than the 
rest of the fingers, so that it can be opposed to them, 
which enables the animals to grasp bodies with great se¬ 
curity, a matter of great importance in climbing animals. 
Their teats are placed on their chest, and the male organ 
is free and pendulous. Their brain is much more de¬ 
veloped than in most other beasts. Linnaeus and some 
other naturalists have included the genus Homo (Man) 
in this order. But a prominent zoological character 
which separates this genus from the rest of the animals 
which are referred to the order, is in the fore limbs alone 
being furnished with an opposable thumb, while the 
