1	Male	2
–	Female	7
2	Spines posterior to juxta (‘above’ juxta in slide preparations) pointing antero-ventrally and forming spinose crests or simple patch1 (Figs 55–58)	3
–	Spines posterior to juxta pointing postero-dorsally and situated on inside surface of spade-like plate (Figs 59, 60)	6
3	Medial field of ventrally projecting spines located adjacent to juxta (Figs 55, 56)	4
–	No medial spine patch adjacent to juxta(Figs 57, 58)	5
4	Clasper with thumb positioned at basal third of distance to apex (Fig. 55); hindwing with dark fuscous terminal shade (Figs 1, 2); occurring east of the Mississippi Valley (Fig. 69)	Lacinipolia vicina
–	Clasper with thumb positioned nearly halfway to apex (Fig. 56); hindwing without dark fuscous terminal shade (Figs 4, 5); occurring west of the Mississippi Valley (Fig. 70)	Lacinipolia teligera
5	Crest of phallus usually with a thin, delicate apically-directed spine (sometimes broken off, in which case base is still evident) (Fig. 61), or if thin spine absent, then entire crest reduced with fewer and smaller cornuti (Fig. 61c); forewing ground colour highly variable, but medial area concolourous with postmedial and antemedial areas, and antemedial line absent or poorly defined; usually with apical pale area that extends through postmedial line into reniform spot; subterminal area usually darker than postmedial area; reniform and orbicular spot often only faintly visible; orbicular spot sometimes flattened and elongated; arid low elevation habitats including shortgrass prairie and sagebrush steppe	Lacinipolia acutipennis
–	Crest of phallus never with a thin, delicate basally-directed spine (Fig. 62), rarely with robust cornutus directed apically (Fig. 62h); forewing ground colour varying in saturation but consistent in tone, with medial area containing brown tones that are lacking in the grey-and-black postmedial and antemedial areas; antemedial line usually well defined; pale apical area not extended through postmedial line; subterminal area not darker than postmedial area; reniform and orbicular spot conspicuous, paler than ground; orbicular spot never highly flattened and elongated; low to high elevation woodland, particularly dry, montane pine and Douglas-fir woodlands	Lacinipolia pensilis
6	Clasper with a thumb-like process on ventral margin, clasper flattened and apex rounded; digitus pointed (Fig. 59); widely distributed, including West Coast states (Fig. 73)	Lacinipolia sareta
–	Clasper without process, shaped like a sinuate spine with a pointed apex; digitus rounded (Fig. 60); West Coast states (Fig. 74)	Lacinipolia dimocki
7	Ostium asymmetrical, like opening of a conch; margin of prevaginal plate straight or slightly convex (Figs 63–66)	8
–	Ostium symmetrical, opening simple; margin of prevaginal plate strongly convex (Figs 67, 68)	1
8	Ostium complex 1.4–1.5 × longer than wide; caudal portion of ostial slit gradually curved (Figs 65, 66)	9
–	Ostium complex 1.0–1.1 × longer than wide; caudal portion of ostial slit sinuate (Figs 63, 64)	10
9	Forewing ground colour highly variable, but medial area concolourous with postmedial and antemedial areas, and antemedial line absent or poorly defined; usually with apical pale area extended through postmedial line into reniform spot; subterminal area usually darker than postmedial area; reniform and orbicular spots often only faintly visible; orbicular spot sometimes flattened and elongated; arid low elevation habitats including shortgrass prairie and sagebrush steppe	Lacinipolia acutipennis
–	Forewing ground colour varying in saturation but consistent in tone, with medial area containing brown tones that are lacking in grey-and-black postmedial and antemedial areas; antemedial line usually well defined; pale apical area not extended through postmedial line; subterminal area not darker than postmedial area; reniform and orbicular spot conspicuous and paler than ground; orbicular spot never highly flattened and elongated; low to high elevation woodlands, particularly dry, montane pine and Douglas-fir woodland	Lacinipolia pensilis
10	Basal half of hindwing conspicuously lighter than marginal portion and forewing (Fig. 6); occurring in southern Great Plains west of Mississippi River (Fig. 70)	Lacinipolia teligera
–	Basal half of hindwing nearly as dark as marginal portion and forewing (Fig. 3); occurring in the eastern United States east of Mississippi River (Fig. 69)	Lacinipolia vicina
11	Ductus bursae highly flattened dorsoventrally, with pronounced ribbon-like oblique fold (Fig. 67); corpus bursae 2–2.5 × diameter of ducts bursae; widely distributed, including West Coast states (Fig. 73)	Lacinipolia sareta
–	Ductus bursae moderately flattened dorsoventrally, with slight oblique fold; corpus bursae 3–4 × diameter of ductus bursae (Fig. 68); West Coast states from Washington to California (Fig. 74)	Lacinipolia dimocki