REPORT OF THE FOREST, FISH AND GAME COMMISSION. 523 



disappeared for a time but were present in some numbers about the middle of 

 August. They were taken a few times in trap lanterns and also in sweeping aquatic 

 vegetation, but the hatchery ceiling was the best collecting ground. The larvae and 

 pupae are very similar in form and habits to those of Sisyra described above. 



Caddis Flies. 



The caddis flies are known to lovers of nature as case worms, so frequently 

 seen at the bottom of streams. Fishermen are also acquainted with these curious 

 larvae, and if one has never seen them, they are comparatively easy to find by 

 examining closely the bottom of almost any body of water. One may see here 

 and there a peculiar, usually somewhat cylindrical case, made of some of the 

 materials found at hand. For example, these cases are not infrequently made of 

 two sticks of wood, one longer than the other, the longer one usually projecting 

 quite a little distance beyond the end of the case proper, and with the intervening 

 space filled by smaller particles of vegetable debris and the interior lined with silk. 

 This species is exceedingly common in many of the brooks of New York State. 

 Other forms use, instead of vegetable matter, grains of sand, small shells or pebbles, 

 and in some species there is no tube, but the larvae lurk in rapidly rushing water 

 under stones, and depend for sustenance upon the exceedingly interesting web or 

 net which is stretched across a very small portion of the running stream. This 

 little creature is predaceous, and catches its food in what is really a water net. The 

 adult insects look very much lik<_ moths. They are soft creatures with four large 

 wings, which are more or less densely closed with hairs or scale-like hairs. They 

 are considered as being closely related to the moths and butterflies, and when one 

 examines both the adults and the case worms themselves this relationship is quite 

 evident. The English fishermen, according to Prof. Miall, know some of these 

 insects under the following names: Blue Dun, Little Red Spinner, Sand Fly, Gran- 

 nom, Turkey Brown, Dark Spinner, Silver Horns and Cinnamon Fly. They are also 

 known as Duns. The inhabitants of these cases are interesting, and resemble cater- 

 pillars very much indeed, though, of course, they have become adapted to living 

 under water. Two forms of these interesting larvae are represented at figures i, 2 

 and 8 on plate 6. These case worms are fed upon by fish to some extent. The 

 studies of Prof. Forbes show that they occurred somewhat rarely in the stomach of 

 the rock bass, forming, perhaps, 15 per cent of its food and but 12 per cent of the 

 food in minnows of the Hybopsis group. Apart from these, they averaged from i to 

 6 per cent of the food in less than half of the species studied by Prof. Forbes. Mr. 



