324 PHYLUM ARTHROPODA. 
be said that the centipedes (Ciidggaga) and the millipedes 
(Diplopoda) are very closely related to one another, and 
-therearetwo 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 
Fic. 170.—A millipede. Fic. 171.—A centipede 
Myriopods as Scolopendredla ; and it is likely that Myriopods 
and Insects are divergent branches from a common 
stock. 
Centipedes and millipedes are characteristically texrestr#l. 
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 Linotenia 
maritima—occur on British coasts. 
