TRICHOPTERA 83 



5. Remove a living pupa from its case, and watch its 

 respiratory movements. 



B. The Study of Preserved Specimens. 

 I. With adult specimens in hand, note. 



1. The general hairiness of wings and body. 



2. The long slender antennae. 



3. The rather small eyes. 



4. The reduced mouthparts bearing two pairs of well 

 developed palpi. 



5. The slender legs with large spurs on the tibiae, usually 

 a different number of these on front and middle legs. 



6. The broad wings, fore and hind of nearly equal size, 

 and of rather similar venation. 



7. The cylindric, thin-skinned hairy abdomen, quite dis- 

 tinct from thorax, and with short appendages at its tip. 



II. With a caddisfly pupa in hand, note. 



1. The appendages, close folded against the body. 



2. The large mandibles. 



3. The gills upon the abdomen — this is the only group 

 of insects that is truly aquatic in its mode of respiration 

 in the pupal stage. 



4. The lateral fringes of the abdomen ; these aid in driving 

 water through the tube when the body is waved up 

 and down. 



5. The spines at the tip, and the teeth on the back of the 

 abdomen. 



