PARANEUROPTERA. 



687 



prothorax is small ; the meso- and meta-thorax are combined, 

 and have their ventral portions pushed forward carrying the 

 insertion of the legs with them ; in the extreme cases the meso- 

 thorax lies very largely above the meta-thorax. The abdomen 

 is long and cylindrical, consisting of ten segments and ending 

 in a pair of forceps-like processes (Fig. 434). Certain 

 structures on the second abdominal segment in the male 



FIG. 434. Anax formosus. Britain (after Migneaux). (The legs are not in a natural 



position.) 



serve as vesiculae seminales, though how the semen is 

 conveyed to them from the opening of the common vas de- 

 ferens 011 the ninth segment is not clear. It is from the second 

 segment however that the female takes up the semen during 

 the nuptial flight. The ova are placed in the water or on 

 some aquatic plant. The larvae are characteristic. They 

 undergo many moults, and after the first three or four, traces of 

 wings are apparent. The labium of the nymph is very large and 

 jointed like a carriage-step ; it is sometimes called the mask. It 



