74 THE ENTOMOLOGIST. 



completely across the wings. This last-mentioned variation 

 is, however, not uncommon ; and I possess several specimens 

 of" C. villica with a similar streak in the hind wings. 



It is difficult to offer any reasonable conjecture as to what 

 may have been the "exciting cause," as Dr. Buchanan 

 White terms it (Ent. Mo. Mag. xiii. 148), of such an aberra- 

 tion as the above from the ordinary form of the species. 

 The larva which produced this specimen was obtained, 

 with several dozen other larvae of the same species, from one 

 locality, near Brighton, and was fed up with them, on the 

 same food-plants, in one breeding-cage. It was, therefore, 

 subjected to the same conditions as to nutriment, light, 

 humidity, and temperature, as the others, not one of which, 

 however, produced any noticeable aberration from the type 

 of the species. 



Having regard to these facts, I am inclined to think that 

 the colorational peculiarities of this specimen must be con- 

 sidered as the result of a diseased condition of its larva ; 

 they cannot be attributed to causes similar to those* 

 constantly operating in certain districts, in the production of 

 melanic or melanochroic forms ; nor to any special conditions 

 of food, light, or temperature, to which, in any locality, a 

 larva in a state of nature may, under peculiar circumstances, 

 be subjected. 



INTRODUCTORY PAPERS ON LEPIDOPTERA. 



By W. F. KiRBY, 



Assistant-Naturalist in Museum of Science and Art, Dublin. 



No. VII. NYMPHALID.E— ACEiEINiE. 



The Acrceina are a rather small group of long-winged 



butterflies, generally of some shade of fulvous, with black 



spots, or black, with white or yellowish markings, and the 



hind wings beneath either striated, or spotted with black at 



the base. The fore wings are partially transparent in some 



species. The palpi of the imago are thick and scantily 



clothed with hair, and the larvae are spiny. The genus 



Acrcea, as it stands, is too extensive, but it cannot yet be 



satisfactorily subdivided, though we may retain the name 



Aciinote, Hiibn., for the South American section, with 



* I. e., the geological formation of a district, and the nature of its mineral 

 productiiius (if any); its geographical position, and the prevailing character 

 of its climate and vegetation. — H. G. 



