AQUATIC INSECTS IN NEW YORK STATE 471 



of the fore wings. Prothorax quadrangular, much narrower 

 than the head and shorter than the mesothorax and the meta- 

 thorax combined; large toothlike angles on the back part of the 

 sides of the head ; three large approximate ocelli facing at about 

 120° from each other; antennae filiform moniliform or slightly 

 serrate in a few species, as long as, or much longer than the 

 head and thorax combined; mandibles prominent, not concealed 

 by the labrum when closed, those of the male more or less elon- 

 gated and annular, incurved, suited only for clasping. Wings 

 numerously veined, the accessory veins of the radial sector ex- 

 tending backward from E2 in both pairs of wings, and media 

 has more than two branches [fig. 26] ; hind wings broad at base 

 and folded in the anal area when at rest; wing expanse 100 to 



Pig. 86 Fore wing of Corydalls cornuta x2 



150mm. Tarsi cylindric; male caudal appendages long and 

 usually strongly forcipate; in the female they are short and 

 simple. 



Larva. When full grown, the larva is about 80 to 90 mm long. 

 The general color is dusky; the head and thorax are supplied 

 above with pretty figured markings; the whole body is supplied 

 with black clavate projections except in the intersegmental folds 

 and on the parts heavily clothed with chitin. The last four or 

 five segments of the abdomen taper toward the caudal end of 

 the body. The first eight segments of the abdomen are each pro- 

 vided with a pair of unjointed lateral filaments, 6 to 7 mm long, 

 somewhat clothed with hairs; the first seven of these segments 

 are each provided with a pair of ventral tufts of tracheal gills. 

 Spiracles are found on each of the firsit eight abdominal seg- 

 ments and on the fold between the prothorax and the meso- 

 thorax, and a rudimentary pair on a fold between the meso- 

 thorax and the metathorax. On the last abdominal segment are 



