CLASS MYRIAPODA. 39 



CHAPTER XI. 



CLASS MYRIAPODA. 



The Mj'riapods are commonly known as Centipedes and 

 Millipedes, and all these names refer to the great number 

 of the feet or legs, as compared with Insects or Spiders, 

 (Greek, miirios, ten thousand ; podes, feet). As a good 

 representative of this class may be taken Lithohms forfi- 

 catus, one of the commonest of British Centipedes. 



The body in Lithohms (fig. i6. A) is elongated and 

 flattened, and exhibits very distinctly a division into two 

 regions — namely, a head [h), and a lengthy body composed 

 of a series of separate rings or segments, each of which 

 carries a single pair of appendages. The entire integ- 

 ument, both over the head and over the body, is hardened, 

 so as to form a strong case, within which the internal 

 organs are contained ; and the appendages to the segments 

 are very distinctly jointed. 



The head is somewhat heart - shaped, and though it 

 really consists of several pieces or segments, these are so 

 consolidated that it appears to form a single piece. The 

 head carries a single pair of long, jointed feelers, known 

 as the "antennae" (Latin, antenna, the yard-arm of a 

 ship), which consist of very numerous short joints. The 

 head also carries upon its two sides a collection of minute 

 simple eyes (fig. i6, C, e), from twenty- two to twenty-four 

 on each side. On its under surface the head bears the 

 opening of the mouth, with a well-marked lower lip behind 

 it — this latter organ being really double (fig. i6, B, I). 



Immediately behind the head, and looking as if it be- 

 longed to it, is a narrow ring which carries a pair of 

 powerful jaws (fig. i6. A, /, and B, /). These jaws are 

 strongly hooked, and are perforated for the purpose of 

 conveying a poison, with which the Centipedes kill their 

 prey, or defend themselves against their enemies. Though 



