226 Nerve-winged Insects; Scorpion-flies; Caddis-flies 



of moss or in a rotten log, in which they pupate, and from which the adult 



fly issues in about two weeks. 



The genus Corydalis (Fig. 311) is represented by a single species, C. cornuta, 



but it is such a conspicuous and wide-spread insect that it is probably the 



best-known species in the whole order 

 Neuroptera. The adult fly is most com- 

 monly called "hellgrammite," while the 

 larvae (Fig. 312), much used by fisher- 

 men as bait, are known as dobsons or 

 crawlers. But other names are often 

 used. Howard lists the following array 

 of names, collected by Professor W. W. 

 Bailey, which are applied to the larva 

 in Rhode Island alone : dobson, crawler, 

 arnly, conniption-bug, clipper, water- 

 grampus, gogglegoy, bogart, crock, hell- 

 devil, flipflap, alligator, Ho Jack, snake- 



FIG. 311. 



FIG. 312. 



FIG. 311. Dobson-fly, Corydalis cornuta, male, with head of female above. (Natural 



size.) 

 FlG. 312. Larva of dobson-fly, Corydalis cornuta. (Natural size.) 



doctor, dragon, and hell-diver. The insect is very common about Ithaca, 

 N. Y., and Professor Comstock of Cornell University gives the following 

 account of its life-history as observed by him there: " The larvae live under 

 stones in the beds of streams. They are most abundant where the water 



