562 NEW YORK STATE MUSEUM 



case and bad no tubercles on the abdomen. Numerous filaments on the 

 abdomen serve as respiratory organs, obtaining oxygen from the water 

 which is kept circulating through the case by the undulatory motion of 

 the body. 



When the time for transformation approaches, the larva closes the 

 opening of its case, sometimes with the same material as that used in the 

 case itself, but frequently with other things. Sometimes only a web of 

 silk is spun across the opening, and in every case sufficient space is left 

 for the circulation of the water. During the pupal period the cases are 

 generally fastened to submerged sticks, stones or other supports. In 

 size the pupa does not differ greatly from the larva. The eyes have 

 become far more prominent. Wings and antennae appear and are folded 

 backward and downward under the body. The legs and palpi are also 

 folded beneath the body. In place of prolegs and hooks, two long tube- 

 like processes (fig. 38) terminate the body. The pupa holds its position 

 by means of hooks on the dorsal side. Generally there are hooks point- 

 ing backward at the anterior edge of several segments, while at the 

 posterior edge of one or two segments is a pair of plates bearing spikes 

 which point forward. The respiratory filaments remain, and breathing is 

 doubtless accomplished by the same method as in the larval stage. 

 When the time of transformation arrives, the pupa leaves its case, climbs 

 up some support, casts its skin and emerges as an adult insect. Some 

 species emerge directly from the surface of the water. 



So far as observed, the adult caddis flies do not feed. They spend 

 their lives near the place of emergence, most of them flying but little, at 

 least durmg the day, but some species may be seen swarming just over 

 the surface of the water. The large number taken by the trap lantern is 

 evidence of the nocturnal habits of the adults. The laying of the eggs 

 was not observed but must of course take place in or directly above the 

 water. Many clusters of eggs were found under the bark of submerged 

 trees, which would lead to the conclusion that in some cases the female 

 insect goes under water to deposit the eggs. The circular cluster of 

 greenish eggs shown in plate 7,^, figure 4 was found suspended on a sub- 

 merged twig under a log floating in deep water. The number of eggs in 

 this cluster was estimated at 450. 



In the description of species given below, there was no opportunity 

 for comparison with other work of the same kind. Fn fact, no descrip- 

 tions of the immature stages of the American species of Trichoptera has 

 heretofore been published, except the paper of Miss Cora Clarke^ which 



1 Clarke, Cora H. Caddice worms of Stony brook. Psycbe. 1891. p. 153. 



