Neuroptera 203 



complex neuration, many cross nervules being present, 

 except in the tiny Coniopterygida: which have the hind- 

 wings markedly smaller than the front pair, and are 

 further distinguished by a white powdery covering. 

 The only wingless genus among the Neuroptera is 

 very scarce and is recognisable by the production of 

 the head into a long snout. 



The order may be divided into ten families (3, 129). 



Sialidse. — The Slalidce or Alder-Flies have a quadrate head bear- 

 ing a pair of long many-jointed, tapering feelers. The three 

 thoracic segments are distinct and sub-equal, while the hindwings 

 are slightly shorter than the forewings, though the neuration is 

 closely alike in both pairs. The females lay their eggs in rows on 

 rushes or grass-stems near water in which the larvse live. The 

 latter are carnivorous and very perfectly adapted for aquatic life, 

 being provided with pairs of jointed gill-filaments on the first seven 

 segments of the hind-body, and a long unjointed tail-process on the 

 hindmost segment. The family includes only about five genera, 

 with a discontinuous range in different parts of the world. The 

 species of Corydalh, found in North and South America and Northern 

 India, are remarkable for their gigantic size and the immense man- 

 dibles of the males (170). 



Raphidiids. — The RaphidUda or Snake-Flies are easily recognised 

 by their narrow elongate prothorax and hind head-region, giving 

 the appearance of a constricted neck. The female is provided with 

 a long ovipositor. The larvz are of the eruciform type, but with- 

 out cercopods ; they live in rotten wood and feed on small insects. 

 The family contains only two genera, and is confined to the northern 

 parts of the Old World and to North America. 



Myrmeleonidse. — The Myrmdeonida or Antlion Flies are, as a 

 rule, large insects with prominent head, bearing a pair of short, 

 clubbed feelers ; the palp of the first maxilla has five segments, 

 that of the second, three. The wings have the nervules at the tip 

 so arranged as to form regular oblong cellules. The larvs of these 

 flies are the well-known " antlions," with powerful quadrate head 

 and stout ovoid body. The mandibles are prominent and slender, 

 grooved on their inner edge; through these grooves the juices of 

 the insects whereon the antlion feeds is sucked into the gullet, the 

 ordinary mouth-opening being closed. Some of these larvje dig 

 conical pits in which they entrap their prey; others hunt it, or 

 lurk in concealed situations. The family is distributed throughout 

 most of the tropical and temperate regions, ranging into southern 

 Sweden, though unrepresented in these islands (fig. 113). 



Ascalaphidae. — The Aualaphldje are nearly related to the pre- 

 ceding family, which they resemble in their structure and life- 



