KEY TO ADULT MALE NORTH AMERICAN MALACOSOMA 



(The genitalic characters are by far the most rehable.) 



1. Lines on forewing darker than background color .... 2 



Lines on forewing Hghter than background color .... 6 



2(1). Epiphysis longer than first tarsal segment of foreleg, about 



% as long as tibia and sickle-shaped (fig. 75); genitalia as 



in figures 12, 33, 37, and 57 disstria, p. 84 



(Also see neustrium, p. 187). 



Epiphysis, if present, shorter than first tarsal segment of 

 foreleg, not % as long as tibia and sickle-shaped .... 3 

 3(2). Outer line on forewing usually distinctly curved toward base 

 of wing near costal margin and meeting it at nearly a right 

 angle as in figure 140; genitalia as in figures 13, 34, 38, and 

 58; distribution — Washington, Oregon, California, and 

 Baja California 4 



Outer line on forewing usually turned toward tip of wing 

 near costal margin or meeting it at an acute angle as in 

 figure 178; genitalia not as in figures 13, 34, 38, and 58; 

 distribution — all of western and northern North America . 5 

 4(3). Color usually brownish; lines on forewing sometimes faint or 

 nearly absent (males in figs. 152-160); distribution — 

 south of a line drawn from Indio, Riverside Co., Calif., 

 along the southern base of the San Bernardino and San 

 Gabriel Mountains (fig. 4) . . constrictum austrinum, p. 99 



Color usually yellowish; lines on forewing more distinct, 

 rarely faint (males in figs. 140-151); distribution — north 

 of a line drawn from Indio, Riverside Co., Calif., along the 

 southern base of the San Bernardino and San Gabriel 

 Mountains (fig. 4) . . . . constrictum constrictum, p. 93 

 5(3). Lines on forewing not indented along veins, and not bordered 

 by a narrow, pale area; inner, outer, and median areas of 

 forewing almost invariably the same uniform color; color 

 varying from yellow to yellow-brown (males in figs. 161- 

 175); genitalia as in figures 14, 32, 39, and 59; distribu- 

 tion — Utah, Colorado, Arizona, New Mexico, Texas, 

 Mexico, and possibly adjoining areas (fig. 1). tigris, p. 102 



Lines on forewing often indented along veins as in figure 249, 

 and often bordered by a narrow, pale area as in figure 261 ; 

 inner, outer, and median areas of forewing usually with some 



