( civ ) 



their mode of distribution on the surface of the wing. 

 Though they may, at any rate in some species, be found 

 sparingly on the general surface, they are much more numerous 

 in a certain circumscribed area along the border of the hind- 

 wing ; in one or two species they appear to be confined to the 

 costal extremity of this area. Along this marginal region 

 they occur in such abundance as to cause a marked difference 

 in the texture of the wing, making their presence plainly 

 visible to the naked eye, and almost deserving the appellation 

 of a "sex-brand." Mixed with them are found in great 

 abundance scales of a different kind ; these are elongated, of 

 the shape of an Indian club, not distally indented, very heavily 

 loaded with dark pigment, and showing especially dark 

 longitudinal streaks. The ordinary scales from the blue 

 portions of the wing are curiously sculptured and apparently 

 unpigmented. 



Nepheroma avatar differs somewhat from its congeners. Its 

 scent-scales are distributed over the general surface of the 

 wing; they ai"e much smaller than in other Xepheronias, and 

 have a correspondingly small disc. 



The species of Leuceronia are exclusively African. In this, 

 as in the preceding genus, we find the scent-scales densely 

 congregated within definite areas, not, however, to the entire 

 exclusion of other parts of the wing. On a cai'eful examina- 

 tion of the wing-surface in L. thahit^.^iiia, argia, pharis and 

 huquetii, a slight depressiou or pucker will be seen at the end 

 of the cell of the hind- wing. This depression is usually visible 

 in both sexes ; in the male it marks the situation where the 

 plume-scales are most certainly to be found. It is a very 

 curious fact that, so far as my observations extend, the plume- 

 scales in Leuceronia argia from Natal and S. Rhodesia (Z. varia 

 of Trimen) are confined to this situation ; whereas in speci- 

 mens from the West Coast, the Kassai region of the Congo, 

 the River Lualaba, and British E. Africa, they are to be found 

 plentifully distributed over the general surface. 



In L. thalassina the lamina is somewhat long and thin, with 

 parallel sides and an e.Kpanded and rounded base. The whole 

 scale is curiously glassy and translucent ; it appears to be 

 entirely devoid of pigment. In L. argia the lamina is longer ; 



