III. SCENT-ORGANS OF EPICALIA, ETC. 
623 
characters which distinguish the patches of E. acontius from those of 
most other species are as follows :— 
First, the difference which is observed between the over- and underlying 
scales ; for it is the general rule for the scent-scales to be all of one 
form, without any distinction between the upper and lower. 
Second, the fact that the pits or sockets in which the scales are 
implanted are placed at about the same distance apart on the scent 
patches (PL B, Fig. 15) as on the rest of the wing (Fig. 14); whereas, 
as a rule, the scent-scales are more closely placed than the ordinary ones. 
The pits of the scent-scales are larger, and surrounded by a dark 
elliptical or circular area, as is also frequently seen in other species. 
Again, it is worth noting that a considerable modification in the shape 
of the wing accompanies the development of the scent-patches. The 
inner (or posterior) margin of the anterior wings is nearly straight in 
the females of E. acontius (PL B, Fig. 10), and in both sexes of E. numilia 
(Fig. 9), but in the males of E. acontius (Fig. 11), it is greatly arched, and 
in such manner as to cover a much larger part of the lower wings. In 
a similar manner the costal border of the hind-wings is enlarged. Hence 
it follows that in the female of E. acontius (Fig. 10) the form of the wings 
approaches more nearly to that of the male E. numilia (Fig. 9) than to 
that of its own male (Fig. 11). 
Closely allied to Epicalia is the genus Myscelia , represented in the 
province of Santa Catharina by M. or sis, Drury. I have recently been 
able to examine a male of this species, in which Herrich-Schaeffer 1 de¬ 
scribes a felted spot (“ filzfleck ”) on the upper surface of the hind¬ 
wing (PL B, Fig. 1 m), between the fifth and seventh nervures, that is to 
say, between the discoidal [radial or second discoidal] and the first branch 
of the subdorsal [subcostal]. It required little to convince me that the 
above-mentioned patch exhales a strong scent, which, like that of E. 
acontius male, greatly resembles musk. The patch, which occupies about 
one-ninth (36 square mm.) of the surface of the wing (315 square mm.), 
also extends a little beyond the nervures which Herrich-Schaeffer assigns as 
its limits. Its colour is entirely black, while the surrounding area of the 
wing, which, like the spot, is overlapped by the fore-wing, is greyish, the 
disc being of a brilliant blue. The structure of the patch differs little 
from that of E. acontius , and it is therefore unnecessary to give any 
detailed description. The scent-scales differ in that they do not greatly 
exceed the ordinary ones in size, while the fore-wings are destitute of 
scent-organs. 
Thus, in respect to the felted patches, the male of Myscelia orsis occu¬ 
pies an intermediate position between Epicalia numilia , which has no such 
structures, and E. acontius , which bears them on the fore-wings as well as 
the hind. In view of these facts, it is permissible to doubt whether any 
1 Prodrom. Syst. Lepidopt, fasc. i., 1864, p. 27, No. 79.—F.M. 
