Class 2. Myriapoda. 



229 



organs, which are filled before coitus, with, spermatozoa, and inserted 

 in the genital aperture of the female.* 



In most Diplopoda {e.g. lulus) the eggs are laid in masses, covered by a small 

 mound, perforated at its apex, and formed of earth and a glandular secretion. 

 Glomeris, however, sun-ounds each egg with a spherical covering of earth. 



The Diplopoda and some Chilopoda have, when they leave the 

 egg, fewer segments and appendages than later j in the former, the 

 newly-hatched young ones have usually only three pairs of legs (that 

 of lulus is quite apodous) ; in the latter there are seven pairs. Other 

 Scolopendridse have the full number on hatching. 



The Centipedes constitute a relatively small division. They are, 

 without exception, terrestrial ; inhabiting damp, shady places, under 

 leaves, in the soil, etc. 



In most points they are so nearly allied with the large class foUowing, the 

 Insects, that it might be thought best to incorporate them with that group. 

 They are, however, regarded here as a distinct class, because they oft'er certain 

 peculiarities which would mark them off as very aberrant Insects, and interfere 

 with the clear definition of that group. 



Order 1. Chilopoda {Scoiojjendra-s). 



The head is flat and bears three pairs of jaws, of which the first 

 maxillae have very often undergone concrescence in the mid-line. 

 The basal joint of the second 

 maxilla also coalesces with its 

 fellow of the other side, whilst the 

 other joints form a palp. The rest 

 of the body, which often consists 



of a very large number of segments, 



is flattened dorso-ventrally; the legs HI^^HhMLsBI^^^Bj^' 



arise far apart from one another 



(Fig. 193 A), from the soft, lateral 



portions of the segment, one pair 



to each segment. The foremost 



pair of legs is very different 



from the rest; it is very strongly 



developed, and forms a pair of stout, 



hook-like organs, at the tip of which 



is the opening of a poison gland pj^ ^^^ ^^^^ ^^ ^^^^^i^^ ^^^^ 



(the p ois on - ol a ws) . The last segmentaofa Soolopendra.frombelow. 



1 . Ti \, 1. o- antenna (the greater part out off), 



pair also is usually somewhat j first maxilla (the greater part covered) , 



modified, being longer than the ^' palp of second maxiUa, p' first pair of 



,^ J J. J 1, 1 tj. legs, 6 its fnsed basal joints, p^ second 



Others and turned back. it ^^j^^f legs.-Orig. 



has already been remarked that 



the genital organs open at the posterior end. 



* In one genus of the Diplopoda, Glomeris, the terminal pair of legs forms the 

 copulatory organs. 



