324 



PHYLUM ARTHROPODA. 



be said that the centipedes (Chilopodd) and the millipedes 

 (Diplopoda) are very closely related to one another, and 

 there are two other distinct orders, Symphyla and Pauropoda. 

 The resemblances are in part resemblances of convergence, 

 not of genuine affinity. Simple wingless insects, known as 

 Collembola and Thysanura, are closely approached by such 



FIG. 170. A millipede. 



FIG. 171. A centipede 



Myriopods as Scolopendrella ; and it is likely that Myriopods 

 and Insects are divergent branches from a common 

 stock. 



Centipedes and millipedes are characteristically terrestrial. 

 Most are very shy animals, lurking in dark places and 

 avoiding the light, but it is interesting to note that at 

 least two Myriopods Geophilus submarinus and Linotcenia 

 maritima occur on British coasts. 



