STONE-FLIES, MAY-FLIES, DRAGON-FLIES, ETC. 261 



males of some of the alder-flies have enormous mandibles. 

 In the snake-flies the prothorax and back part of the head 

 are elongated to form a long " neck," and the female has a 

 long ovipositor. The larva of the alder-flies is aquatic, and 

 most of the abdominal segments carry a pair of segmented, 

 fringed gill-filaments (Fig. 119); it returns to land to pupate. 



The Ant-lion flies {Myrmeleonidce) are not unlike dragon- 

 flies, but the antennae though short are conspicuous and 

 clubbed, and the hind wings are decidedly smaller than the 

 front wings. The larvae are known as ant-lions : they have 

 enormous mandibles, which are grooved and so adapted to 

 the maxillse as to form tubes; they dig beautifully sym- 

 metrical pitfalls in dry soil, at the bottom of which they lie 

 concealed, to seize and suck dry with their powerful grooved 

 mandibles any unwary insect that may fall in. 



The Ascalaphidcs also are like dragon-flies, but are dis- 

 tinguished by their long antennae ending in a knob. The 

 larvae are quite like ant-lions, but do not make pitfalls. 



The Nemopteridce are recognised by their extremely long, 

 narrow, oar-shaped or racquet-shaped hind wings. Their larvae 

 are like ant-lions, but have a neck of extraordinary length. 



The Mantis-flies {MantispidcE) resemble small mantises, 

 having the same elongate prothorax and the same raptorial 

 fore legs for striking and grasping insect prey ; but they 

 may be distinguished by the wings, which are subequal in 

 size and alike in consistence — the hind wings also not fold- 

 ing like a fan in repose. The eggs of Mantispidce are stalked. 



The Lacewings or Aphis-lions {Chrysopidce) are delicate 

 insects with long antennae, four filmy net-veined wings, and 

 (in life) shining golden eyes. The eggs are attached to 

 leaves, etc., by very long stalks. The larva has enormous 

 mandibles like an ant-lion, and feeds on aphids. 



The Coniopterygid(z are tiny Neuroptera somewhat 

 resembling the males of some of the bark-lice (Coccidce) upon 

 which they feed. The wings are not net-veined, and the 

 posterior pair are extremely small. 



So far as one can see behind the veil, the order Neuroptera 

 is directly beneficial to man, though it is not known that any 

 particular Neuropteron is hostile to any specific pathopoeic 

 insect. 



