58 



lito'a rather than Phyciodes, and the markings of under side give it 

 place near Hoffrnanni and Gabbii. I have a singular variety of Har- 

 risn\ bred by me in 1877. The normal larva at last stage is red-fulvous, 

 crossed by red stripes, much as in Phaeton. One of the brood at last 

 stage came up almost wholly black, the fulvous being restricted to a 

 few specks and dots on back of each segment. The butterfly from this 

 larva is black on both sides, the fulvous pattern obscured, as if washed 

 with black. 



ON THE GENERIC DISTINCTION OF 

 MEGONOSTOMA. 



By a. G. Butler. 



In a paper describing the early stages of " Colias Eurydice,'" Mr. 

 W. H. Edwards advocates sinking the genus Megonostoma as a syn- 

 onym of Colias, on the ground chiefly that the species of the two 

 groups do not show generic differences in the preparatory stages. 



It is seldom, indeed, that my opinion on entomological matters dif- 

 fers from that of Mr. Edwards, but in the matter of genera we do not, 

 as the saying is, think through one quill. 



In a large group like Papilio I hail with joy the creation of any 

 genus founded upon easily discoverable structural characters as being 

 a real blessing to one who has to deal with the Papiliones of the world, 

 and when that genus has been thoroughly broken up I shall certainly 

 adopt the whole of the fragments as genera. 



A genus is avowedly a convenience; in Lepidoptera it is, and 

 always has been, based upon characters to be found in the imago; and, 

 since the Lepidoptera have been scientifically studied, it has been 

 considered imperative that such characters should be structural. I 

 believe that generic differences commence in the imago, and therefore 

 that strong resemblances may be looked for in allied genera; such dif- 

 ferences as may be shown in color certainly do not indicate distinct 

 genera, as is evidenced by the larvae of the different species of Macro- 

 glossa; whereas, on the other hand, certain characters are indicative of 

 family distinction, as in the case of the species formerly associated 

 under Acronyda. 



Mr. Edwards says that Reakirt has indicated certain appendages 

 which he calls " Eupronychia," as the most important character for 

 distinguishing his genus from Colias; well, it seems that as these ap- 

 pendages are apocryphal, Megonostoma is to be abandoned; yet, in my 

 ' ' Revision of the Genera of the Sub-family Pierinse' ' (Cistula Ento- 

 mologica; Vol. I, Part III, pp. 33-58, Plates I-IV, 1870), for which I 

 traced the wing of nearly every genus then known and reproduced it 

 on stone, I did not see fit to sink Reakirt's genus. If Mr. Edwards 



