52 Key to Families of North American Insects. 



elongated wings, the fore pair often widened at the basal angle. (Euthya- 



tira, Habrosyne). CYMATOPHORIDM THYATIRIDJE 



81. Tongue entirely absent; wings usually with clear spots before apex. (Apate* 



Iddes.) EUPTEROTIIXffi 



Tongue distinct, usually well-developed; wings fully scaled; moths of moderate 

 size and inconspicuous colors, the body rather stout and densely hairy; 

 hind tibiae with two pairs of stout spurs. "Prominent:?." (Datana [D. min- 

 istra, Yellow-neck caterpillar] Heterocimpa, Schizftra [S. (=(Edemasia) 

 concinna, Red-hump Apple-caterpillar]) (PI. 10, fig. 228) NOTODONTIDJE 



32. Spiracles (tympanic openings) at base of abdomen small and subdorsal; first 



anal vein usually partly present; subcosta in hind wing slightly bent at the 

 base and but little enlarged, the humeral angle not expanded; last branch 

 of media and first branch of cubitus stalked in the fore wing; brightly colored 

 moths, usually with hyaline spots on the wings. (Phryganidia.) 



DIOPTER 



Tympanic opening almost always conspicuous and swollen, lateral; first anal 

 vein absent in both wings; subcosta of hind wing sharply bent or much 

 enlarged at the base, almost always with a brace-vein extending to the base 

 of the frenulum; usually small or moderate sized moths of delicate form, 

 with large, finely-scaled wings. (Paledcrita [P. vernata, Spring canker- 

 worm], Alsophila [A. pometaria, Fall canker-worm], Tephroclystis, Rheu- 

 maptera, Hydri6mena, Petr6phora, Edis, Sciagraphia, Cymatophora [C. 

 ribearia, Currant span-worm].) GEOMETRIDjE 



33. Subcosta and radius in hind wings either fused for a very short distance, then 



sharply divergent, or separate from the base, or connected by a weak cross- 

 vein; spiracles at base of abdomen inconspicuous 34 



Subcosta sharply divergent from the radius at the extreme base, then sharply 

 bent and touching, fusing with, or closely parallel to it, or connected by a 

 strong crossvein; spiracles at base of abdomen conspicuous, lateral (see 



couplet 32) A few GEOMETRIC^ 



84. Antennae not scaled beyond the basal joint. (SATURNOIDEA.) 35 



Antennae closely scaled on the upper side 36 



35. Two anal veins; first branch of media in fore wings fused or stalked with the 



radial stem; medium-sized or large moths with stout, hairy bodies and 

 strong wings. (Anisdta, Cither&nia, Basildna. (CERATOCAMPlDsE) 



CITHERONIIDJE 



First branch of media separate from the radial stem; with only one anal vein, 

 or else the upper discocellular vein (the crossvein at the end of the discal 

 cell, between the last radial and the media) long and longitudinal; moderate, 

 large or gigantic moths, with broad and usually strikingly colored wings. 

 (Samia [S. cecropia, Cecropia moth], Callosamia [C. promethia, Promethia 

 moth], Tropoea [T. luna, Luna moth], Telea [T. polyphemiis, Polyphemus 

 moth], Autdmeris [A. io, lo moth].) SATURNIID. 



36. Subcosta of hind wing sharply divergent from the radius from close to its 



base 37 



Subcosta and radius parallel at base, connected by a weak crossvein 39 



