MYRIAPODA. 



145 



In addition to the parts of the mouth proper, they have two 

 pairs of " foot-jaws," of which the second is hooked and per- 

 forated 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 consequently able to inflict extremely severe and even 



FIG. CO. Centipede (Scolopendrci). 



dangerous 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 antennae 

 are composed of not less than fourteen joints each. 



The Millipedes (Fig. 61) are repulsive-looking but perfectly 



FIG. 61. Millipede (lulus). 



innocent animals, which feed principally upon decaying vege- 

 table matter. The body, in the ordinary millipedes, is round- 

 ed and worm-like, and the segments are so amalgamated that 

 each apparent body-ring gives origin to two 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 antennae are short, and are composed of no 

 more than six or seven joints each. 



The European millipedes are all of small size, but an Amer- 

 ican 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 antennae are five-jointed, forked, and provided with jointed 

 appendages. There are no tracheae, and respiration is carried 

 on by the skin. It is very .small, and is found inhabiting 

 decayed leaves and damp situations. 



