31 G .T. A. LINTNER. 



presented the following gradations : head ranging from red ti a gl is>v 

 l)l;ick ; spines of the head, from red at base and black above with white 

 aiiiiulatiuns to the branches, to wholly black; spines of extreinitic'^. 

 from black below and red above, to wholly red ; dorsal spines, from red 

 b;inded with white, and black tipped, to entirely red; lateral rows of 

 spines, from pale red almost white, to ferruginous; body with pustula- 

 tions from white to rufous; linings of body, from well defined and con- 

 tinuous stripes, to lines simply indicated by interrupted markings. 



After their transformation to the pupal state, several of the above 

 were found to have fallen victims to their natural enemy Pteromnln^ 

 /v(//e.s-.vv« Harris. From four chrysalides especially observed, above one 

 liumlred of these parasites emerged from each, a few words i-especting 

 which. — in illustration of the remarkable development of the sexual in- 

 stinct with which we are so frequently presented in the insect world — 

 may not be out of place in this connexion. Escaping from their co- 

 coons contained within the chrysalis one or more small holes were eaten 

 iiy tlieiii. usually In the wing-cases, through which they came tbrth with 

 fully exp;mded wings and in perfect condition, as rapidly as one could 

 follow another. No sooner had a male made his exit, than he at once 

 sought out and united with the opposite sex, quickly passing with vibra- 

 ting wings and antennae from one to another: and so extreme was the 

 ardor impelling them to their unions, that several were observed intent- 

 ly watching at the holes through which their companions were to 

 emerge, and instantly appropriating each female as she made her ap- 

 pearance. 



As the result of the above larval collections, about one hundred and 

 ten inter rogationh were obtained, and not a single amhrosa. Some mi- 

 nor differences of shading were presented, but none sufficient to war- 

 rant classification in accordance with the previous larval grouping. 



The pupa cases from which umhro.-ia emerged, were lain aside for fu- 

 ture comparison, but when opened after the lapse of two or three years, 

 they were found to be almost entirely powdered by the destructive Ait- 

 fhrrnus varius Fab. Unless my recollection is much at fault, they were 

 of a delicate purplish cast, quite in contrast with the ferruginous hue of 

 intcrrogafimiis ; and with several of the dorsal spines having a notable 

 degree of transparency. 



The observations above recorded, render it probable that the speci- 

 mens of wnbrosa obtained, were the progeny of one parent. We may 

 also infer a close larval resemblance to interrogation^* and also a pre- 



*Mr. Edwards has obtained the larvse in W. Virginia, and reared numljera of 



