126 BOMBTCID^. 



It may be thought that the strongly falcate shape 

 of the anterior wings, in many of the Saturniae, 

 would afford a good mark of distinction ; and in 

 certain instances such may be the case. But this is 

 a character that requires to be used with caution, 

 for in many cases it is only a sexual distinction. A 

 careful comparison of the two sexes in all the species 

 we can find either figured or described, has con- 

 vinced us that there are few genera in which the 

 male and female present such marked differences. 

 The male, as is usual among insects, is much smaller 

 than the female, and the whole outline of his form 

 is, so to speak, comparatively contracted. Hence 

 there is almost always a strong tendency in the 

 exterior line of the upper wings to be curved in- 

 wards, or assume a falcate shape. The outline of 

 the female, on the contrary, is comparatively full, 

 and the tendency of the line in question is rather in 

 an opposite direction. The species, accordingly, in 

 which the fore wings of the male are most decidedly 

 falcate, have this form much less strongly marked 

 in the female; where the former are not very strongly 

 falcate, in the female they become subfalcate (H.Pro- 

 methea may serve as an example) ; while the females 

 of subfalcate winged males have the exterior out- 

 line of their fore wings either straight or slightly 

 curved outwards. Nay, if our views regarding one 

 of the species be correct, there exists an example of 

 the fore wings of the male being strongly falcate, 

 while those of the female are as obviously rounded 

 laterally, describing a convex curve. 



