NEUROPTERA. 



155 



Oedee IV. — NEUROPTERA. 



The genuine Neuroptera are those net-veined insects which have a complete meta- 

 morphosis. The larvae are entirely unlike the adults, as they are long and slender, 

 with more or less cylindrical bodies, some, as the caddis worms and larval forceps flies 

 (JPanorpa), bemg much like caterpillars. The pupae are never active, and are in many 

 cases protected by a cocoon. A' neuropterous pupa is a good deal like the chrysalis 

 of a moth, differing, however, besides other characteristics, in the wings and limbs 

 being free and movable, not soldered to the body. 



The adult Neuroptera are only net-veined in the Sialids and gauze-winged flies 

 (Hemerobidae), and the cross veins are much less numei'ous than in the false Neuroptera. 

 There is one feature in which the Neuroptera almost invariably differ from the Pseudo- 

 neuroptera, and this is in the nature of the extremity of the under lip (ligula), which 



Fig. 226. — Corydalus comutus, horned oorydalus, female. 



is not cleft at- the tip, but is broad and flat. Moreover, the prothorax is often small 

 and collar-like, though large and square in the two lower famiUes. In the higher 

 groups of caddis flies and forceps flies the thorax is more or less rounded, spherical, 

 like that of moths, and the fore wings are in the caddis flies rather smaller than the 

 hinder pair. 



The family Sialids (the members of which are thick and stout, with a large, square 

 prothorax and net-veined wings, and usually aquatic larvae) is represented by one of 

 the largest and most singular insects in this country ; nothing of the sort existing in 

 the Old World. It is the Corydalus cormctus of Linnajus. Though exceedingly for- 

 midable and alarming in appearance, it is in reality entirely harmless. Moreover, it 

 flies mostly by night, though we have known one case of its flying in the day-time and 

 alighting on a person's clothes. It is fully two inches in length, while the wings expand 

 a little over six inches, the two pairs being of nearly the same size. An interesting 

 peculiarity of this insect is the remarkable size of the jaws in the male ; in the female 

 the jaws are very large, flat, and toothed at the extremity, but in the male they are 

 remarkably long and slander, cylindrical, not toothed, the sharp tips crossing each 

 other. Their only use is evidently for seizing the soft, somewhat yielding body of the 



