396 Mr. A. G. Butler on the Genus Acronycta. 



LXIV. — Notes on the Genus Acronycta of Authors and its 

 Position in the Glassijication of Ileterocerous Lepido^tera. 

 By A. G. Butler, F.L.S., F.Z.S., &c. 



In the ' Transactions of the Entomological Society' for 1879 

 I proposed (pp. 313-317) to break up the old genus Acro- 

 nycta and distribute it, chiefly on account of its very distinctive 

 larval cliaracters, amongst the various families of Bombyces 

 &c. to which the peculiarities of the larvse seemed to show- 

 affinity. It must, however, be borne in mind that my con- 

 clusions were based chiefly upon the larvai of the British 

 species and the published illustrations of Abbot ; nevertheless 

 I examined the neuration of the species in each group, com- 

 paring it with that of each of the families to which the larval 

 types seemed to ])oint. 



Unfortunately, at the time when I wrote my paper the 

 importance of the position of certain veins in the wings of 

 moths, as having more than generic value, was not so fully 

 appreciated as at the present time ; therefore, although I 

 correctly represented the venation of the Notodontidse, I failed 

 to see that the position of the median branches and lower 

 radial of the primaries in that family precluded the possi- 

 bility of any Acronycta being regarded as even remotely 

 allied to it. On the other hand, it is now known that the 

 Liparida3 and Arctiidse are much more nearly related to the 

 Noctuee than was formerly supposed ; so that the similarity 

 in neuration is by no means surprising, nor is there any 

 reason why larval characters found in the former should not 

 also occur in a genus of Noctua. 



A recent study of the transformations of Acronycta in 

 Abbot's unpublished volumes has now clearly shown that the 

 differences in the clothing and outline of the larvae charac- 

 teristic of the Bombycid families already referred to occur in 

 various species of the same group in Acronycta.^ and so are 

 valueless as indicative of their affinities. 1 am therefore 

 obliged to renounce my former opinion and admit that 

 Acronycta is in truth a genus of Noctua3, probably nearest 

 allied to Folia. 



The sections into which Acronycta has been divided may 

 still be used (as having the value of numerals only) to indicate 

 the near affinities of the species ; and, as the Museum series 

 is represented by nearly eighty species, 1 propose to indicate 

 them below. I must, however, first point out that Acronycta 

 simplex of Walker is Xylomyges crucialis of Harvey, and 



