113 



be deposited by the ? upon Alniis viridis. The following is the 

 record of changes : 



Eggs deposited July 8. 

 Larva hatched July 13. 

 "■ first moult July 15. 

 " second moult July 18. 

 " third moult July 22. 

 " showed retractile horns July 24. 



THE PREPARATORY STAGES OF PLUSIA BILOBA.— . 



Stph. 



By G. H. French. Carbondale, III, 



Egg. — Nearly globular, the base slightly flattened, the apex 

 slightly inclined to a blunt cone. At the apex is an irregularly 

 punctured space ; from near the base run a number of ridges, 

 about twenty of which reach the punctured apical space, many of 

 them not reaching this point, as they are the same distance apart 

 throughout. The depressions between the ridges are filled with 

 a series of quadrate punctures in the centre of each of which is a 

 small elevation. There is no apical depression. Size .02 of an 

 inch in diameter ; color white, with a faint creamy tinge ; dura- 

 tion of this period five days. 



Young Larva. — Length .07 of an inch. Body white or with 

 a very pale tinge of green, head and top of joint two black, pili- 

 ferous spots black, showing very prominently a single black hair 

 arising from each. Legs 12, for which reason the larva loops 

 when walking ; when at rest the front part of the body is gener- 

 ally elevated, though not straightened out like a geometrid. 

 Before eating the food placed in the dish each larva ate a portion, 

 if not all, of its egg-shell, after which it remained quiet for a time. 

 Duration of this period three days. 



After First Moult — Length .16 of an inch. Head and top 

 of joint two pale amber, the jaws a little darker. Body pale 

 translucent green ; the piliferous spots large tubercle-like, tipped 

 with black, and each suporting a black hair. The body nearly 

 cylindrical, truncate posteriorly. Duration of this period three 

 days. 



After Second Moult. — Length .33 of an inch. Color pale 

 green, the dorsal line darker. Subdorsal line whitish, as also 

 two other lines in the dorsal space. Stigmatal line greenish- 

 white through the middle of the body, appearing to be com- 

 posed of two lines. Above the stigmatal lines, on joints 5 to 9, 

 is a bright black spot on each joint, the last one small. Pilifer- 

 ous spots concolorous with the body ; the hairs pale, each two- 

 thirds as long as the diameter of the body. Head pale amber, 



