CENTIPEDES AND MILLEPEDES. 



549 



tively short in front, but increase rapidly in length till they are nearly as 

 long as the body. The proportions of the limbs, etc., however, vary con- 

 siderably in different species ; the legs are very brittle. These centipedes 

 feed on insects, and are very active. Most of them are inhabitants of warm 

 climates (the family is unrepresented in England), and the colour is usually 

 greenish when alive, but is liable to change rapidly after death. They have 

 only sixteen joints, and are provided with compound eyes instead of ocelli. 



The Lithobiidce are represented in Britain by Lithobius forficatus (Linn.), 

 which has two clusters of ocelli, fifteen pairs of legs, increasing iri length 

 hindwards, and long antennae, with more than forty joints. 

 It is a repulsive-looking, reddish-brown creature about an 

 inch long, with a comparatively broad body. It is very 

 active in its movements, and feeds chiefly on worms ; and 

 is often unearthed by digging in garden-mould or in a 

 dung-heap. (Fig. 21.) 



The Scolopendridce generally have four simple eyes on both 

 sides, antennae with about twenty joints, and usually twenty- 

 one pairs of legs. The body is often very broad and flat- 

 tened. The family is represented in South Europe, 

 and the species are often of considerable size, sometimes 

 measuring more than a foot in length. Their bite is as pain- 

 ful and dangerous as that of a scorpion, though they are 

 sometimes used as an article of food by the natives of the 

 countries where they are numerous. They are generally of a 

 brown or reddish colour, or banded with green and yellow. 

 In Britain we have only one small blind yellowish species of the 

 family, Cryptops hortensis (Leach), which is harmless. 



The Geophilidce. are very long slender centipedes, with (Linotcenia eras- 

 fourteen-jointed antennae, neither compound eyes nor ocelli, s j^fied ^ 

 and from thirty-one to one hundred and seventy-three leg- 

 bearing segments, each provided with a pair of rather short legs. They are 

 nocturnal creatures, of a whitish or yellowish colour, and are remarkable 

 for emitting a pale phosphorescence which has led to their being called 

 electric centipedes. They are found in Britain as well as in warmer 

 countries. 



Fig. 22. ELEC- 

 TKIC CENTIPEDE 



ORDER CHILOGNATHA (MILLEPEDES). 



The millepedes are distinguished from the centipedes by their feeding chiefly 

 on vegetable matters ; and, consequently, they have imperf orate foot-jaws, and 

 are not venomous. Their bodies are generally convex above, and more or less 

 flattened beneath ; and while the first three segments behind the head, cor- 

 responding to the thorax in insects, bear only one pair of legs each, the remain- 

 ing segments bear two pairs. The head of the millepede is composed of a 

 single segment only. They vary much in size ; and dead specimens become 

 extremely brittle, the segments separating at the least touch. 



The Polyzoniidce are semi-cylindrical creatures, with small heads, and from 

 30 to 100 or more joints, and capable of rolling themselves up spirally. The 

 mouth-parts are modified into a sucking proboscis. The best known species, 

 Polyzonium germanicum, (Brandt), is about two-fifths of an inch long. 



