454 NEUROPTERA 



mouth in their early life, and one of the ordinary biting type in 

 adult life. 



This is a very unusual condition, being the reverse of what 

 we find in Lepidoptera and some other of the large Orders, 

 where the mouth is mandibulate in the young and suctorial in 

 the adult. The suctorial condition is in Hemerobiidae chiefly 

 due to modification of the mandibles ; but this is never the case 

 in the Insects that have a suctorial mouth in the ' imaginal 

 instar. Nearly all the Hemerobiidae are terrestrial Insects in all 

 their stages ; a small number of them are, to a certain extent, 

 amphibious in the larval life, while one or two genera possess 

 truly aquatic larvae. The metamorphosis is, so far as the 

 changes of external form are concerned, quite complete. There 

 are no wingless forms in the adult stage. 



The classification given by Hagen 1 and generally adopted 

 recognises seven sub-families. These we shall mention seriatim. 



Sub-Fam. 1. Myrmeleonides or Ant-lions. Antennae short, 

 clubbed, the apical space of the wing with regular, oblong 

 cellules. 



FIG. 299. Tomateres citrinus. S. E. Africa. (After Hagen.) 



The ant-lions in their perfect state are usually unattractive 

 Insects, and many are nocturnal in their habits ; the species of the 

 genus Palpares and allies (Fig. 299) are, however, of more handsome 

 appearance, and attain a large expanse of wing. No member of the 

 sub-family is an inhabitant of Britain, though species of the typical 

 genus Myrmeleon are common in Central and Northern Europe. The 



1 Stettin, ent. Zeit. xxvii. 1866, p. 369 ; this author has also sketched a classifi- 

 cation of the larvae in P. Boston Soc. xv. 1873, p. 243. 



