244 Nerve-winged Insects; Scorpion-flies; Caddis-flies 



chiefly at night, as large numbers have been taken in trap lanterns by Betten. 

 The eggs are laid, according to this observer, 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. A spherical cluster found suspended on a sub- 

 merged twig under a log floating in deep water contained 450 eggs. 



Some of the caddis-fly larvae can be readily kept in an aquarium. 

 Almost any kinds found in ponds will live in aquariums, where their feed- 

 ing-habits and transformation may be observed. The caddis-worms that 

 build odd cases of small sticks laid crosswise live contentedly in an 

 aquarium and are most interesting' to watch. The complete life-history 

 of no single caddis-fly species has yet been worked out completely, and the 

 specific identity of but few of our larvae is known. For three California 

 species Geo. Coleman, a student of Stanford University, has obtained adults 

 by putting wire-screen cages over the larvae in the streams. In these cages 

 the larvae had room enough to hunt food successfully, and they lived, except 

 for the circumscribing of their territory, perfectly naturally. Betten has 

 similarly reared imagoes from four kinds of larvae in the Adirondack Moun- 

 tains. 



The following keys will enable the collector to classify either his caddis- 

 worms (larvae) or caddis-flies (adults) to families: 



KEY TO FAMILIES (ADULTS). 



Spines on the legs, three simple eyes (ocelli). 



Four spurs on tibiae (second long segment) of middle legs PHRYGANID^S. 



Two or three spurs on middle tibiae LIMNEPHILID.*:. 



No spines on legs, only hairs or spurs. 



Last two segments of palpi (mouth-feelers) not elongated and flexible. 



Palpi of males 5-segmented; ocelli often present RHYACOPHILIDJE. 



Palpi of males 4-segmented; ocelli absent. 



No spurs on front legs HYDROPTILID^E. 



Spurs on front legs SERICOSTOMATID^E. 



Last segment of palpi elongate and flexible; palpi hairy. 



Basal segment of antennae long and thick, wings slender, no ocelli . LEPTOCERID^E. 



Basal segment of antennae shorter, wings broader, last segment of palpi composed 



of numerous subsegments HYDROPSYCHID^E. 



KEY TO FAMILIES (x ARV^). (AFTER BETTEN.) 



Larva with head bent downward at an angle with the body; tubercles generally present 

 on the first abdominal segment; lateral fringe generally present; gill filaments, 

 when present, usually simple. 



Hind legs more than twice as long as the first pair; cylindrical case of sand and small 

 stones LEPTOCERID.E. 



Hind legs not more than twice as long as first pair. 



