66 THE CANADIAN ENTOMOLOGIST. 



Most aquatic larvae spend the period of their chrysalis state in the 

 water, and only emerge therefrom when ready to pass into the perfect or 

 winged state ; but the insects forming the group to which this larva 

 belongs, leave the water while they are still in the larval state, and do not 

 usually become pupae for several days or even weeks thereafter. Hence 

 the Creator, to meet their necessities, has given them a double system of 

 respiration — a set of gills to breathe with in the water, and a set of 

 breathing holes, or spiracles, to breathe with upon land. In this larva the 

 gills assume the form of paddle-like appendages, and are placed one pair 

 upon each of the seven front segments of the abdomen, while the spiracles 

 are arranged in the usual manner along the sides of the body. After 

 leaving the water the larva crawls rapidly about, chiefly in the night time, 

 in search of a safe and suitable place in which to spend the chrysalis stage 

 of its existence, usually selecting the under surface of a flat board or 

 log, or burrowing under some large stone. Before attaining its object, it 

 sometimes wanders as much as a hundred feet from the water's edge, and 

 an instance is given of one which crawled up the wall to the roof of a 

 one-story buildings and then tumbled accidentally down the chimney, to 

 the great dismay of the good woman of the house. At this stage of their 

 existence they are sometimes used by fishermen for bait, and having a 

 very tough skin, one larva often suffices to catch several fish. They can 

 pinch pretty sharply with their strong jaws, and they use the processes at 

 their tail to assist them in climbing. 



After a suitable hiding place has been selected, the larva forms a rude 

 cell in the earth, and here changes to an inactive chrysalis (see fig. 9, b.) 

 In this figure the wing cases are slightly spread apart from the body to 

 show their shape and structure, whereas in nature they are closely appresaed 

 to the sides of the body. The larva leaves the water usually about the 

 beginning of June, and by the end of that month, or the beginning of 

 July, the perfect insect bursts its bonds and appears in the winged state. 



In this form it measures, when its wings are spread, from four and a 

 half to five inches ; these, as shown in the figure, are gauze-like and 

 covered with an intricate network of veins. The fore wings are streaked 

 with dark brown and sprinkled with whitish dots, of which latter there are 

 also a few on the hind wings. The male (fig. 9, c) is remarkable for its 

 enormous jaws, which are very long and hook-like, while the female 

 (fig. 9, d and fig. 10) has short jaws. The flies hide themselves in 

 obscure holes and corners during the day, and become active as the shades 



