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JOURNAL OF VARIATION. 



No. 7. Vol. III. July 15th, 1892. 



THE GENUS ACRONYCTA AND ITS ALLIES. 



By Dr. T. A. CHAPMAN. 

 {Continued from page gg.) 



\CRONYCTA (Bisulcia) ligustri. — This species differs 

 from the groups Viminia and Ciispidia more than 

 they do from each other. If it is to be kept within 

 the genus Acronycia, then most certainly such 

 species as Clidia geographica and Siinyra nervosa must be placed 

 in the section Viuiinia, and not in separate genera. 



Ligustri differs from the others in the form and sculpturing 

 of the pupa, and also in the form, habit and general facies of 

 the full-grown larva, even making full allowance for the 

 immense variety that Acronycta allows amongst its adult larvae. 

 It agrees with Acronycta, however, in its two most essential 

 characters — viz., the flat dome-shaped egg (less than a hemi- 

 sphere) very like that of psi, and in the young larva having a 

 " weak " eleventh segment, and having, indeed, an undoubted 

 Acronycta form and aspect, although it has no dark segments — 

 except the black head, and this even is pale on emergence from 

 the egg. 



The egg (PI. VIII., fig. 8) is of a pale pearly green, almost 

 colourless, very translucent, i.i to 1.2 mm. in diameter, quite 

 as flat as any of the others, about one-third its diameter in 

 height. The ribs are 60 in number ; the micropylar area is 

 rather larger than usual, and the ribs do not increase in number 

 outwards by intercalation or division so much as is usual in 

 other species. The figure is faulty in not showing a large 

 micropylar area, and in showing little or no branching of ribs. 

 In one instance, two ribs joined together outwards, and so 



