PLTJSIA ORICHALOEA. 101 



had the good fortune to beat ten specimens of a larva 

 which, though exactly like that of PI. gamma, but a 

 little larger, produced in July nine beautiful PI. ori- 

 chalcea. Three others were obtained, one each by 

 Messrs. Archer, Cross, and Raynor, of Ely, but were 

 not reared. Of the earlier stages of the larvae I 

 cannot speak, as those beaten were all past, or near, 

 their last moult. As far as I could see, their colour, 

 size, and markings are exactly those of PL gamma. 

 There are two fine white lines down the back from 

 the third to the penultimate segment, with the dorsal 

 vessel showing darker green between them ; oblique 

 white lateral lines on each of these segments. On 

 the second and third segments and on the anal seg- 

 ment, there are five irregular white lines, which unite 

 together in front, in the direction of the head. The 

 spiracles are white and small, except the last, which 

 is conspicuously larger than the rest. But the most 

 striking feature of this larva is its wonderful power of 

 extending and withdrawing the first three or four 

 segments of its body, and reminding one of the larva 

 of Chserocamjoa elpenor, or of the common earth-worm. 

 When full-fed the larvse spun a flat oval pad of white 

 silk on the side of the muslin bag in which they were 

 reared, and thereon remained for twenty-four hours 

 or longer, perfectly motionless, in a horseshoe-shaped 

 form, the head in close proximity to the tail. After 

 this interval of rest they proceeded to spin the rest of 

 their cocoons, which were soon completed, being thin 

 and transparent enough to allow of the easy observa- 

 tion of every movement of the larva inside. The 

 cocoon, when finished, is oval, with the longer axis 

 perpendicular, and the larvae all pupated with the 

 head upwards. They took a week to pupate after 

 the cocoons were completed, and remained in pupa 

 just a fortnight, the female in all cases emerging 

 twenty-four hours sooner than the male. The pupa 

 of PI. orichalcea may be at once distinguished from 

 that of PI. gamma, which is wholly black, by its 



