36 



I will take the liberty of giving each a designation by which they may 

 be recognized. The three forms may be distinguished as Angusi, An- 

 gusi (a), Ayigusi (b), Grote. 



The first is the normal form, the fore wings of which have none of 

 the black shading of the others. Angiisi (a) has a narrow, dense basal 

 shade in the direction of, and just reaching the sub-reniform. A71- 

 gusi (b) is the most remarkable; the black shade, which occupies but a 

 small space on the wing of the preceding, is in this enlarged to nearly 

 one-third the surface of the wing; it commences with a sharp point at 

 the base, and gradually enlarges, until it reaches the reniform and sub- 

 reniform, both of which it incloses in its track. The reniform, how- 

 ever, is never obliterated, but with its lighter color shows conspicuously 

 through the dark cloud. There is here, however, sometimes a partial 

 or complete interruption, but not in the strongest marked examples. 



These three forms of Angusi I have raised in considerable numbers, 

 and in about equal proportions. I have also captured many of the 

 imago. They are generally to be found under the loose scales of the 

 hickory bark, and, like some other allied forms, they are not easily 

 started. Repeated raps with a rod are sometimes necessary to move 

 them from their lair. 



While I can see no reason whatever for confounding Angusi with 

 Insolabilis, I am even still more surprised that Residua should have 

 been brought into the same relation. In Angusi there is some resem- 

 blance to Insolabilis, but in no particular can this be said of Residua, 

 unless it is in the blackish fringe of secondaries, in which there is a 

 partial, but not an exact, resemblance. Had the reference been made 

 to Obseura I would not have been surprised, and would have hesitated 

 to offer a protest, but the fringe I suppose acted as an obstacle in the 

 way. In Insolabilis the fringe is always black, and in Angusi gen- 

 erally so, but I have in my collection an Angusi (b), the fringe of which 

 is as white as any Obseura I have ever seen. Residua and Obseura are 

 quite variable in the color of the fringe; some of the latter are as dusky 

 as the general run of the former. Were it not for the dusky suffusion 

 of primaries and generally darker fringe of secondaries. Residua could 

 not be distinguished from Obseura. They are, with these slight excep- 

 tions, so much alike I would not be surprised if they should yet prove 

 to be the same species, but I would not like to jump to this conclusion 

 without good and sufficient proof established by breeding or otherwise. 



Hundreds of Obseura have passed through my hands; I am also 

 familiar with their habits, and from my own personal knowledge I have 

 no hesitation in saying that it and Simulatilis are identically the same; 

 the latter was described from the largest, and the former from the 

 smallest examples; there is really no other difference. 



I might here say that I have a very singular Obseura in my collec- 

 tion raised from the larva. It is of a brownish or smokv color; head 



