21 
bands, giving them a peculiarly bristly or hairy appearance. The 
antenne are very stout, much longer than before, and distinetly 
tapering. The rostrum is stout and reaches between the anterior and 
median cox. Legs as in previous stage, though longer and stouter. 
Sixth generation; third or pre-pupa stage.—Length of body, 0.6 to 
0.8"". In this stage they are also densely covered with hair-like 
secretion resembling still to a great extent the second larve, except 
that they are still larger and stouter, and that they have already 
acquired wing pads. The antenne are now very long and stout, the 
third joint being longer than the posterior tibiz, slightly tapering 
and without a trace of annulation, and with the usual movable thumb 
and three stiff bristles on the apex. 
Sixth generation; fourth or pupa stage.—Length of body, 1 to 
1.6™". They are in every particular like the pre-pupa, except that 
Fic. 9.—Hormaphishamamelidis: Sixth generation, second stage; a, dorsal view; b, dorsal view 
denuded, showing arrangement of pores—much enlarged (original). 
the wing pads and the antenne are still longer, and that the annu- 
lation of the third joint of the future imago may be more or less 
distinctly seen through the transparent skin. They are of the same 
dark color as before, with the head and prothorax paler, and the 
eyes, thoracic lobes, and wing pads blackish. The digitules are appar- 
ently simple and bristle-like. 
Sicth generation, fall migrant (Fig. 10).—Having east their fourth 
or final skin, they acquire wings and, after feeding for some time to 
attain complete maturity, forsake the birch and migrates back to 
witch-hazel to deliver themselves of the ultimate or sexual generation. 
Each migrant, according to size, contains from seven to fifteen or per- 
haps more larvz. Migration continues for about a month and a half, 
according to conditions of the season and other natural causes, and 
commences usually toward the end of August and terminates during 
the early part of October. In general appearance they are essentially 
