156 INVERTEBRATE ANIMALS. 
for the discharge of a poisonous fluid. The bite of the common 
European species is perfectly harmless to man, but some of 
the tropical forms attain a length of a foot or more, and are 
li Mi 
Fig. 75.—Centipede (Scolopendra). 
consequently able to inflict extremely severe and even danger- 
ous bites. The true centipedes are further distinguished by 
the number of legs not being indefinitely great (usually from 
fifteen to twenty pairs), and by the fact that the antennz are 
composed of not less than fourteen joints each. 
The Millipedes (fig. 76) are repulsive-looking but perfectly 
innocent animals, which feed principally upon decaying vege- 
Fig. 76.—Millipede (Jz2zs). 
table matter. The body in the ordinary millipedes is rounded 
and worm-like ; and the segments are so amalgamated that each 
apparent body-ring gives origin to ¢wo pairs of minute thread- 
like feet.. The mouth is destitute of the powerful jaws which 
are found in the centipedes, the legs are indefinitely numerous, 
and the antennz are short, and are composed of no more than 
six or seven joints each. 
The European millipedes are all of small size, but an 
American species is stated to attain a length of more than half 
a foot. 
A third family has been established for a curious little 
creature called Pauropus. In this, the body consists of only | 
ten segments, and there are no more than nine pairs of legs. 
The antenne are five-jointed, forked, and provided with jointed 
appendages. There are no trachee, and respiration is carried 
on by the skin. It is very small, and is found inhabiting 
decayed leaves and damp situations. 
