58 WILLIAM T. M. FORBES 



12. Antennae extending at least three-fourths the length of the wings; labrum 



normal . . . 13 



13. Fourth segment of abdomen free from third; antennae and hind legs not sub- 



equal in length, and seldom extending beyond tip of wings 14 



13. Fourth segment soldered to third; antennae and hind legs subequal and extend- 



ing beyond tip of wings 15 



14. Labial palpi visible; last segment with two dorsal spines; setae i closely approxi- 



mate on mid-dorsal line on middle abdominal segments. . . Tischeriidae (p. 145) 



14. Labial palpi invisible; last segment with two lateral spines; setae i normal, 



well separated Lyonetiidae (Bucculatrix) (p. 148) 



15. Abdominal segments 3 to 7 each with two deep punctures at the anterior 



margin near the mid-dorsal line; segments 8 to 10 together shorter than 

 segment 7, not separated by distinct incisures. 



Lyonetiidae (Phyllocnistis) (p. 148) 



15. No such pits on dorsum; abdominal segments 8 to 10 relatively longer. 



Gracilariidae (p. 161) 



16. Cremaster developed with a distinct stem, longer than thick. 



Tortricidae (Peronea) (p. 376) 



16. Cremaster not developed, its hooks attached directly to body 17 



17. Body J:eavily chitinized; dorsal spines or setae on abdomen in transverse rows; 



first abdominal spiracles invisible 20 



17. Body lightly chitinized; dorsal spines irregular; spiracles visible on first 



abdominal segment 18 



18. Abdominal segments with spines on anterior part and setae on posterior part; 



large conical tubercles behind several abdominal spiracles. 



Megalopygidae (p. 101) 



18. Abdominal segments without areas of fine setae; no tubercles behind the 



spiracles 1!) 



19. Labial palpi exposed between maxillae, which are less than half length of 



wings Eucleidae (p. 102) 



19. Labial palpi concealed by maxillae, which are more than half length of wings. 



Pyromorphidae (p. 113, 



20. Mesothorax less than twice as long as metathorax; maxillae quadrangular, 



widely separated, divergent Hepialidae (p. 66) 



20. Mesothorax more than twice as long as metathorax; maxillae longitudinal, their 



tips often meeting in midventral line; or all appendages obsolete 21 



21. Third abdominal segment movable on second; segments with an anterior row of 



spines and a posterior row of setae Psychidae (p. 140) 



21. Third abdominal segment fixed; segments with anterior and posterior rows 



of spines Cossidae (p. 516 ) 



22. Pilifers distinct, the labrum with three lobes, usually separated by a T-shaped 



suture (fig. 29) 23 



22. Pilifers absent, labrum simple or obscurely bilobed 31 



23. Maxillary palpi present; antennae never fusiform and wider toward apex; fore 



femora usually visible 24 



23. Maxillary palpi absent 25 



24. Epicranial suture absent, fronto-cly peal about half visible; eighth segment of 



abdomen free from the seventh in male; no deep dorsal furrow between ninth 

 and tenth segments of abdomen Yponomeutidae (Atteva) (p. 337 ) 



24. Epicranial suture distinct at sides; sometimes running into suture between 



head and thorax at middle (except in the Phycitinse which have a deep groove 

 between ninth and tenth segments of abdomen) ; fronto-clypeal suture 

 absent; eighth segment fixed Pyralididas (p. 523 ) 



25. A deep groove between ninth and tenth abdominal segments dorsally; fore 



femora exposed Pyralididse (Epipaschiinae) (p. 604) 



25. No deep groove between ninth and tenth segments 26 



