174 THE ENTOMOLOGIST. 



the only explanation for this burst of melanism which he could 

 suggest was, that he had been reckless as to the species of grass 

 upon which he fed the larvae. He subsequently sent me some 

 larvEe, which I fed upon different grass every day, with the 

 result that I did not rear a single typical example, all being 

 melanic and much dwarfed. When I gave up collecting our 

 British moths some years since I got rid of my specimens with 

 the exception of a single pair, which are now in the general 

 collection at the British Museum. 



"Mr. White says that his V. UrticiB is of the usual size, but 

 with the characters of Poltjcldoros ; this description would answer 

 very well for V. CaUfornica, and, considering the great general 

 resemblance between all the species of the group, the case is not 

 a very remarkable instance of reversion. 



"In a brood of about fifty V. Urticce, reared by me, there was 

 a single very dark and small specimen which, although not like 

 V. Poltjcldoyos, may have been a case of reversion to something 

 more nearly allied to V. C-alhnm ; and some of the species allied 

 to the latter are very dark indeed. 



"Lastly, as about half the species in the genus have the 

 wings far more deeply dentated and subcaudate than the other 

 half, whilst many gradations between the extremes of these two 

 types exist, it seems most natural to look for the progenitor in a 

 species which exhibits variation of form in accordance with the 

 season, so that one may account for the prevalence of one type 

 in one climate and of the other in another ; and to regard two 

 species of the same type as descended one from the other, 

 especially when these two co-exist throughout Europe (or nearly 

 so), seems to me to be a supposition in the highest degree 

 improbable." 



INTRODUCTORY PAPERS ON LEPIDOPTERA. 



By W. F. Kirby, 

 Assistant in tlie Zoological Department, British Museum. 



No. XVIT. NYMPHALID.E— NYMPHALIN/E {continued). 



There are several genera allied to Hypolimnas, all Indian 

 or African, which are chiefly remarkable for their resemblance to 

 species of Z)r(»(<».s or Acrcea. The former are Indian; and two 

 species will serve to illustrate them. One is Hestina assimilis, a 



