52 PROCEEDINGS OF THE NATIONAL MUSEUM vol.90 



16. Ostium large, round (fig. 265) nigrinotella (Busck) (p. 101) 



Ostium spindle-shaped (transverse) (fig. 255) argillacea (Walsingham) (p. 98) 



17. Ostial opening definitely in anterior half of genital plate (fig. 261). 



costimacula, new species (p. 102) 

 Ostial opening not definitely in anterior half of genital plate 



(figs. 262, 263, 264, 266, 267, 268, 269, 270, 273) 18 



18. Ostial opening about middle of genital plate (figs. 266, 269) 19 



Ostial opening definitely in posterior half of genital plate (figs. 



262, 264, 267, 268, 270, 273) 20 



19. Anterior to ostium a strongly sclerotized crescent-shaped bar; 



posterior to ostium a small sclerotized rectangular area 



(fig. 269) amissella (Busck) (p. 117) 



Anterior to ostium an elongate, slightly curved, sclerotized mar- 

 gin; no sclerotized area posterior to ostium (fig. 266) 



nebulosa (Zeller) (p. 110) 



20. Signum distinctly 4-pointed (figs. 262, 264, 270, 273) 22 



Signum not 4-pointed (figs. 267, 268) 21 



21. Genital plate broad, with a gently concave, narrow, sclerotized 



anterior margin; ostial opening on extreme posterior edge 



(fig. 268) latipalpella Barnes and Busck (p. 118) 



Genital plate narrow with a broad, convex anterior margin; ostial 

 opening not reaching extreme posterior edge of genital plate 

 (fig. 267) flavicomella (Engel) (p. 105) 



22. Ostial opening occupying more than half length of genital 



plate (figs. 262, 263, 270) 24 



Ostial opening occupying half or less than half length of genital 



plate (figs. 264, 273) 23 



23. Signum large, with small, scattered teeth; lateral points much 



larger than anterior and posterior points (fig. 273) 



costosa (Haworth) (p. 113) 

 Signum small, with strong teeth; lateral, anterior, and posterior 



points about equal in length (fig. 264) antennariella, new species (p. 108) 



24. Posterior and anterior points of signum of about equal length 



(fig. 263) senicionella (Busck) (p. 107) 



Posterior and anterior points of unequal length (figs. 262, 270) 25 



25. Anterior point of signum longer than posterior point (fig. 262) 



canadensis (Busck) (p. 104) 

 Anterior point of signum shorter than posterior point (fig. 

 270). sabulella (Walsingham) (p. Ill) 



26. Signum situated in extreme anterior end of bursa copulatrix 



(figs. 242, 243, 245, 247a, 271) 27 



Signum not situated in extreme anterior end of bursa copula- 

 trix (figs. 241, 246, 254, 256, 257, 258) 31 



27. Ostial opening at extreme anterior margin of genital plate (fig. 



271) psoraliella (Walsingham) (p. 121) 



Ostial opening not at anterior edge of genital plate (figs. 242, 



243, 245, 247) 28 



28. Ostial opening at extreme posterior edge of genital plate (fig. 



242) clemensella (Chambers) (p. 68) 



Ostial opening not at posterior edge of genital plate (figs. 243, 



245, 247) 29 



