170 UNITED STATES NATIONAL MUSEUM BULLETIN 2 76 



of incurvum are the only ones which have an epiphysis (fig. 77) which 

 even approaches M. disstria''s in length, but disstria's, is shaped differently 

 (fig. 75). 



MALE TERMINALIA (figs. 35, 16-18, 41-43, and 61-63).— The 

 terminalia are indistinguishable from those of the southeastern popula- 

 tions of Af. californicum as described under "comments" (page 128), but 

 many specimens can be separated from the northwestern populations of 

 M. californicum by the greater distance between the prongs of the 

 accessory claspers as described there (page 128). This is of no importance, 

 however, since the northwestern populations of M, californicum do not oc- 

 cur where incurvum is found. Posterior edge of seventh sternite (figs. 61- 

 63) not distinctive, varying from heavily sclerotized and uneven to prac- 

 tically unsclerotized and smooth, often with a median notch. Genitalia 

 (fig. 35) virtually identical with those of M. californicum (fig. 36); 

 somewhat similar in shape to those of Af. americanum (fig. 31), but the 

 absolute size of incurvum is smaller for moths of similar size in other 

 respects (compare the size of the eighth sternite of americanum (fig. 40) 

 with those of incurvum in figs. 41-43). Also, the arc of curvature of the 

 "arms" of the eighth sternite near the points is usually greater for 

 incurvum than for americanum. 



ADULT FEMALES (females in figs. 285-308).— Color more 

 uniform than males, varying from fairly dark chocolate-gray-brown to 

 lighter, more yellowish-brown. Lines on forewings appearing light or 

 dark, usually both, since the darker median area is usually bordered 

 by a narrow pale area. Lines usually with some small indentations 

 along the veins, but never meeting to cut off "islands." Median area 

 usually darker than inner or outer areas, but sometimes about same 

 color. Hindwing generally about same color as median band of 

 forewing, and sometimes crossed by a faint lighter line. Lower surface 

 of both forewings and hindwings about same color as upper surface 

 of hindwing, and crossed by a single contrasting line. Epiphysis varying 

 from absent to about as long as second tarsal segment of foreleg on 

 some specimens. 



FEMALE TERMINALIA (figs. 93-96, 103).— The terminalia are 

 indistinguishable from those of the southeastern populations of M. 

 californicum as described under "comments" (page 128), but many speci- 

 mens can be separated from the northwestern populations of M. cali- 

 fornicum (page 128) by the dorsal ovipositor lobes, which are often 

 reduced in the northwestern populations, but are usually quite distinct 

 for incurvum. This is of no importance, however, since the northwestern 

 populations of AI. californicum do not occur where incurvum is found. 

 Genital plate varying from nonsclerotized to completely sclerotized; 

 ostium centrally located. 



