80 



PSYCHE. 



[May 1 891. 



cornis. The egg is larger, being .03X. 02 of 

 an inch as against .025X.015 in the case of 

 longicortiis. In color, instead of being dirty 

 white it is dull yellowish. The hexagonal 

 pits are exactly like those on the egg of 

 longicomis, but are perhaps smaller, as there 

 are 30-35 in its entire length as against 20 

 only in the smaller egg of longicomis " 



The larva is said to differ from that of 



D. longicornis in being larger and in 

 the presence of the two small tubercles 

 at the posterior edge of the caudal plate. 

 The pupae of the two species are said to 

 differ only in size. 



Two dipterous parasites of D. 1 2- 

 punctata are known to Professor Riley, 

 one a Tachinid obtained from the larva, 

 the other coming- from the adult. 



DESCRIPTIONS OF THE PREPARATORY STAGES OF TWO FORMS 

 OF CERURA CINEREA Walk. 



BY HARRISOX G. DYAR, NEW YORK. 



I have discussed the differences be- 

 tween the Eastern and Western forms 

 of the imago in the Canadian ento- 

 mologist 1 and in the present article 

 consider the larval stages. The larvae 

 of the two forms are much alike ; the 

 differences, after eliminating certain ap- 

 parent ones clue to individual variation, 

 narrow to the greater prominence of 

 crimson in cinereoidcs and its some- 

 what shorter caudal filaments or stema- 

 poda, to use Dr. Packard's term. My 

 examples of cinerea were nearly without 

 crimson spots in the dorsal patches, but 

 Professor Lintner has allowed me to see 

 some notes by Professor Riley on this 

 species in which they are described as 

 present, and doubtless the character is 

 variable. In the following some allow- 

 ance should be made for individual 

 variation. 



1 Can. ent., v. 22, p. 253. 



Cerura cinerea Walker. (Eastern 

 form.) 



Egg. Slightly more than hemispherical, 

 the base flat. Color, dead black; diameter 

 1.2 mm. 



Laid singly ; the larva hatches by eat- 

 ing a hole in the side but does not de- 

 vour the rest of the shell. 



Larva : Second stage. Head rounded, the 

 sutures deep, blackish brown; width 1 mm. 

 Cervical horns brown, spinose as are the 

 caudal filaments, the latter twice annulated 

 with pale yellow. Body green, a blackish 

 brown subdorsal line on each side, the space 

 between them over the dorsum filled in with 

 the same color except in three patches (1) on 

 joint 3 posteriorly, joints 4 and 5 quadrate, (2) 

 on joints S-10 pointed anteriorly, and (3) a 

 rounded one on joint 12. These are of a more 

 yellowish green than the body color. Exten- 

 sile threads black, once annulated with white. 

 Length of larva 7 mm; of tails 5 mm. 



Third stage. Head subquadrate, rounded, 



