52 ILLINOIS BIOLOGICAL MONOGRAPHS [52 



jj. Long axis of prothoracic spiracle horizontal 



(Pig. 69). PSYCHIDAE 



ii. Pi group on mesothorax unisetose (Pig. 40) ; setae 



alpha of segment 9 farther apart than setae beta. 



j. Setae beta closer together on segment 9 than on 



any other abdominal segment, usually on the 



same or adjacent pinacula (Fig. 42). 



TORTRICIDAE 



jj. Setae beta at least as far apart on segment 9 



as on other abdominal segments, never borne 



on the same or adjacent pinacula (Fig. 56). 



k. Mandibles large and conspicuous, extending far 



beyond margins of labrum (Fig. 72) ; larvae 



borers, in later instars very large. 



COSSIDAE 

 kk. Mandibles small, larvae leaf-feeders, always 

 small. 



I. Coxae of metathoracic legs twice as far apart 



as wide ; setae indistinct, prolegs small. 



COSMOPTERYGIDAE 



II. Coxae of metathoracic legs never twice as far 



apart as wide. 

 m. Adfrontals reaching vertical triangle or 

 nearly so ; front extending two thirds 

 of the distance to the vertical triangle, 

 when shorter forming an attenuate point, 

 or head not depressed, not held hori- 

 zontally, 

 n. Crochets biordinal in most species ; ad- 

 domen with alpha and beta remote, 

 segment 8 with rho never caudodorsad 

 of spiracle, 

 o. Fourth ocellus much closer to third 

 than to sixth, second closer to third 

 than to first. OECOPHORIDAE* 

 oo. Third ocellus not so closely associated 

 with second and fourth. 



GELECHIIDAE* 

 nn. Crochets uniordinal. 



*Characters separating these two families and the next not constant. 



