560 AN INTRODUCTION TO ENTOMOLOGY 



F. Anterior branch of the radial sector in the fore wings forked. 



P- 562 Hydropsychid^ 



FF. Anterior branch of the radial sector simple, p. 564 



■ PSYCHOMYID^ 



BB. Maxillary palpi with fewer than five joints. 



C. Maxillary palpi with four joints; ocelH present. Males, p. 564... 



Phryganeid^ 



(iC. Maxillary palpi with two or three joints. 



D. Maxillary palpi filiform, with cylindric smooth joints; fore tibiae; 



with a single spur. Alales. p. 568 Limnophilid^ 



DD. Maxillary palpi hairy or scaly, appressed against and often covering 

 the face; fore tibiae with two spurs. Males, p. 569. . Sericostomatid^ 



TABLE OF TRICHOPTEROUS LARV^ 



The following table will aid in the classification of caddice-worms. It is 

 based on a more detailed table of the family characters of trichopterous larvae 

 given by Lloyd ('21). 



A . Anal prolegs not fused in median line to form an apparent tenth abdominal 

 segment. 



B. Abdomen much wider than the thorax, p. 561 Hydroptilid^ 



BB. Abdomen not much wider than the thorax. 



C. Dorsal surface of the ninth abdominal segment with a chitinous shield. 



p. 560 RHYACOPHILIDiE 



CC. Dorsal surface of the ninth abdominal segment without a chitinous 

 shield. 



D. Tracheal gills present, branched, p. 562 Hydropsychid^ 



DD. Tracheal gills absent. 



E. Labrum entirely membranous , white, p. 563 . . Philopotamid^ 

 EE. Labrum entirely chitinized. 



F. Frons long, extending back to the caudal margin of the head. p. 563 



POLYCENTROPID^ 



FF. Frons normal, p. 564 Psychomyid^ 



AA. Anal prolegs fused in median line so as to form an apparent tenth segment. 

 B. Dorsal surface of the labrum with a row of twenty or more heavy bristles. 



p. 567 CALAMOCERATIDiE 



BB. Dorsal surface of labrum normal. 



C. Labrum much longer than broad, p. 567 Odontocerid^ 



CC. Labrum broader than long. 



D. Metanotum with three pairs of plates, p. 568 Limnophilid^ 



DD. Metanotum soft. 



E. Mesonotum soft or with one pair of minute plates, p. 564 



Phryganeid^ 



EE. Mesonotum chitinized. 



F. Femur of hind legs divided into two segments or apparently so. 



p. 566 Leptocerid^ 



FF. Femur of hind legs not divided. 



G. p. 569 Sericostomatid^ 



GG. p. 566 Molanid^ 



Family RHYACOPHILID^ 



The larvae are campodeiform ; they live in rapidly flowing streams 

 with stony bottoms. The American species of this family represent 

 two subfamilies. The members of one subfamily, the Rhyacophilin^, 



