40 



BULLETIN UNIVERSITY OF MONTANA. 



THE ALEXANDRA SULPHUR. 

 Eurymus alexandra, Edwards, Fig. 36. 



Fig. 36 Eurymus alexandra, female with expanded wings; male 

 showing unaer side. From specimens taken at Bigt'ork. 



Butterfly— Expanse of wings of females 2-2.3 inches, 50-60 mm.; of 

 males, 1.75 inches, 45 mm. Male pale canary yellow, the black border 

 much narrower than in philodice or eurytheme; a fine yellow line 

 borders the black on outer margin; base of wings, thorax and abdomen 

 with considerable black; anterior of thorax, antennae and legs roseate; 

 under side of fore wings much paler than upper, uniform: under side of 

 hind wings pale greenish gray, sprinkled with black scales; discal cell 

 of hind wing silver, without rings; black border above showing through 

 wing from below. Female larger than male, without black border above; 

 sometimes the apex of fore wings is sprinkled with black, giving indica- 

 tions of markings; wings paler than in male, sometimes almost white; 

 discal spot in fore wings black, oval, sometimes with yellow splash in 

 the middle; on hind wing orange yellow, usually double; under side, 

 silvery gray, yellow only at the base and on inner margin of the prim- 

 aries; discal spot of hind wings silvery, with brown margin. Discal spot 

 of fore wing dark brown with light spot m center; the roseate of the 

 male repeated on the female, continuing around the outer border of the 

 wings. 



Early Stages— Caterpillar uniformly yellowish-green, with a white 

 band on each side, broken with orange dashes running through it. The 

 chrysalis resembles that of philodice, is yellowinsh green, darkest on the 



