44 SYNOPTIC KEY 



20(23) Aquatic forms, usually inclosed in some sort of a case. 



21 



21(22) Case (a silken cocoon) filled with air and connected 

 with the internal atmosphere of an aquatic plant. 

 Chrysomellidae, in part. (Lutz, 362; Comstock, 574.) 



Order Coleoptera 



22(21) Case (usually made from pebbles, sand, or plant 

 material cemented together with silk) not filled with 

 air. (Lutz, 57; Comstock, 186.) 



Order Trichoptera 



23(20) Pupae not aquatic. 1 24 



24(27) Head prolonged into immovable beak. 25 



25(26) Antennae long enough to reach beyond the middle of 

 the body; borne on the front of the head between the 

 eyes nearly in line with their lower margins. (Lutz, 

 56; Comstock, 184.) Order Mecoptera, in part 



26(25) Antennae not long enough to reach beyond the middle 

 of the body; borne on the sides of the head or beak in 

 front of the eyes. Rhyncophora, in part. (Com- 

 stock, 590; Lutz, 393.) Order Coleoptera 



27(24) Head not prolonged into an immovable beak. 28 



28(31) Pro thorax distinct (i.e., standing out as a distinct 

 segment) ; mouth parts formed for biting. 29 



29(30) Appendages and wings folded tightly against the body; 

 antennae either lamellate or passing around the sides 

 of the head and backward between the body and the 

 dorsal angle of the folded legs; cells or cocoons when 

 present, always elongated. (Lutz, 280; Comstock, 

 494.) Order Coleoptera, in part 



