FIELD BOOK OF INSECTS. 



tail filaments, hind wings larger than the front ones and, 

 in some cases, with curious reminiscences of their former 

 life in degenerate gills at the bases of the legs. A single 

 female may lay as many as 6,000 eggs, dropping them 

 either promiscuously into the water or done up in a loose 

 packet. Less than a hundred species have been described 

 from North America. 



MEGALOPTERA 



This "pigeon-hole" in the classification of insects 

 contains the former Neuropterous family Sialididae. As 

 an Order, it now has two families of its own: SIALIDID.E 

 (in a limited sense) and CORYDALID^E. Before telling 

 about the only species concerning which I have actually 

 been asked by laymen, I will slip in a few words about some 

 of its relatives. This order is probably more primitive 

 than Neuroptera and its members differ from Neuroptera 

 in having the hind wings broad at the base and folded, 

 fan-like, when at rest. Species of Sialis (the only genus 

 in Sialididae) are called Alder-flies or Orl-flies and differ 

 from other members of the order in having no ocelli. 

 Their larvas are aquatic; carnivorous; each of the first 

 seven segments of their abdomen bears a pair of five- 

 jointed appendages, and a similar (but longer and un- 

 jointed) appendage forms a kind of tail. The larvae live 

 buried in the bottom of streams but they crawl out and 

 bury themselves in above-water earth to pupate all 

 Megaloptera have complete metamorphosis and so do 

 pupate. The Corydalidae differ from the Sialididae by 

 having three ocelli, when adult, and two hooked fleshy 

 projections, instead of a single "tail," on the hind end 

 of the abdomen of the larva. The family is divided into 

 genera, two of which concern us: Chauliodes, in which 

 the adults have the hind corners of the head rounded, and 

 the larvae have no hair-like tufts at the bases of the lateral 

 filaments of the abdomen; and Corydalis, in which the 

 adults have the hind corners of the head sharply angled 

 and the larvae have hair-like tufts at the bases of the lateral 

 filaments. The species of Chauliodes are called Fish- 

 flies. The adults are grayish or brownish, with whitish 



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