40* 



and two hundred females, mostly stuck to the inked bands on fourteen apple 

 and three elm trees. There was not an autumnata to be seen among them. 

 This may show, in a rough way, the numerical disproportion between the 

 sexes — one male to five females. 1 also suspect that the males lly about one 

 or two days before the appearance above ground of the females. 



Egg, larva, and pupa. — The eg<>' is oval-cylindrical, yellowish, the shell 

 much thinner, and less dense, and rougher than in A. autumnata. They are 

 laid in piles irregularly, not in tlat cakes, side by side, as in autumnata. The 

 larva is brown as a ground-color, with three broken, partly obsolete, while, 

 dorsal threads, a broad, brown, subdorsal band, nearly twice as wide as the 

 dorsal striped area. A lateral, broad, whitish area broken by two broken brown 

 lines, the lower part of the band being whiter than on the upper edge, and 

 forming a narrow broken line more or less marbled with brown. This broken 

 white line is the only line contrasting with the brown body, while in 

 autumnata there are as a rule several such white lines. Beneath, a broad, 

 whitish, median line, contrasting with the flesh-colored under surface. 



The tendency to variation is in this species shown to consist in the body 

 being whiter, the dorsal area being pale, with a dark lateral line, some speci- 

 mens being pale, with a broken lateral line sometimes represented by isolated 

 spots. It thus appears 1 hat the variation is in the direction of autumnata. 

 The two species are of about the same size, though several out of the twenty- 

 seven autumnata are larger than any of the seven hundred and thirty vernata 

 examined. 



Length of vernata, 0.70-0.80; of autumnata, 0.90 inch. 



In one example, which on repeated examination I unhesitatingly pro- 

 nounce to be vernata, as it agrees in all its other characters with that species, 

 there is a third pair of abdominal legs on tin' sixth segment! These legs are 

 well developed, as much so as in most autumnata, and provided with a perfect 

 crown of hooks. 



The pupae of the two species I have not myself studied. Mr. Riley 

 describes that of vernata (male) as pitted, the wing-sheath extending to the 

 fifth abdominal ring, with the terminal spine simple; while the pupa of 

 autumnata (male) is not pitted, is darker brown than vernata, the wings 

 reaching to the sixth abdominal ring, and with the terminal spine bifurcate. 



The pupa of autumnata differs, Mr. Riley states, in the same way as in 

 the male, but is relatively stouter and more arched dorsally. ami with a broad, 



