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



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

 rosition in the Classification of Ileterocerous Lepidoptera. 

 By A. G. Butler, F.L.S., F.Z.S., ykc. 



In the ' Transactions of the Entomological Society ' for 1879 

 I proposed (pp. 313-317) to break up tlie old genus Aero- 

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

 larval characters, amongst the various families of Bombyces 

 t^c. to which the peculiarities of the larva3 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 neuratlon 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 

 ap[)reciated as at the present time ; therefore, although I 

 correctly rc])resented the venation of the Notodontidae, 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 

 Liparidae and Arctiidas are much more nearly related to the 

 Noctuas than was formerly supposed ; so that the similarity 

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

 reason Avhy larval characters found in the former should not 

 also occur in a genus of Noctua3. 



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 Abbot's unpublished volumes has now clearly shown that the 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 larvaj 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 Noctuse, probably nearest 

 allied to Pulia. 



The sections into which Acronycta has been divided may 

 still be used (as liaving 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. 1 must, however, first point out that Acronycta 

 simplex of Walker is Xylomyges crucialis of Harvey, and 



