XI. SCENT-SCALES OF MALE DIONE 
663 
a length of about 0*7 mm. An opaque, expanded clavate base, which 
recalls the scent-scales of some “Whites” [Pierinae] , is followed first by a 
slender transparent stalk of about one-eighth of the total length, then by an 
elongate, narrow lancet-shaped section which again contracts into a slender 
stalk, finally by a narrow, elongate, rounded and fringed terminal plate. 
The scales which, in a densely packed semicircle, surround the scent-scale 
area are three times as long as the other scales, and differently formed: 
they appear to furnish a sort of protective fence to the scent-scales. 
Among the scent-scales of other butterflies known to me, those of 
various Satyridae are somewhat similar to Dione vanillae. 
In colour and marking, and especially in the silvery patches on the 
under side of the wings, Dione vanillae comes so close to many of the 
Fritillaries, e.g. the German Argynnis aglaia , that I once more examined 
these latter butterflies for scent-scales. On those parts of the hind-wing 
covered by the fore-wing, where I had previously sought them, I had 
found none; but I have now discovered them, as in D. vanillae , on the 
nervures of the fore-wings. In the males of Argynnis aglaia and niobe, 
they appear to be confined to veins 1-4, and are not united into groups, 
but irregularly distributed. Their shape is similar to those of Erebia 
goante (PL H, Fig. 9). A more exact description may well be left to those 
who are able to examine them in a fresh condition. 
Finally I give a synopsis of the occurrence of scent-scales in the above- 
mentioned species. 
Heliconius 
Eueides 
Golaenis dido 
Dione juno 
Dione vanillae 1 
Argynnis aglaia and niobe 
Fore-wing veins 7-8 
55 
55 
55 
55 
55 
55 
55 
55 
55 
55 
55 
5» 
7-8 
7-8 
2-8 
2-6 
1-6 
1-4 
Hind-wing veins 0 
0 
1-3 
,5 1"7 
„ 1-6 
55 
J5 
55 
55 
0 
0 
1 In this species, as well as in A. aglaia and A. niobe, the figures for the fore- and 
hind-wings are accidentally transposed in the original table.—E.A.E. 
