YI. SCENT-ORGANS OF ANTIRRHAEA 
635 
he has incorrectly drawn the mane of the fore-wings, giving to the hairs a 
wrong direction. 
I consider, therefore, in view of the errors and omissions in the existing 
descriptions and drawings of the scent-organs of Antirrhaea archaea , that 
it is desirable to figure and describe them afresh. 
The inner margin of the fore-wing forms in the female (Pl. E, Fig. 1), 
a nearly straight line from the base of the wing to the end of the internal 
[submedian] nervure: in the males, on the contrary (Fig. 2), the inner 
margin forms, between these points, an almost regular arc of 120 degrees 
of a circle whose centre lies at the apex of the angle formed by the 
median nervure and its first branch. Furthermore, the internal [sub- 
median] nervure, after making an obtuse angle 1 near the base, is straight 
in the females, curved like an S in the males. Thus in this sex the area 
included between the internal [submedian] nervure, the median and its first 
branch is larger in the ratio of 4 to 3, and the greater part of this area is 
occupied, on the under surface of the wing, by the characteristic mane of 
pale hairs. This mane commences at a short distance from the base of 
the wing, the line of insertion following for a little more than two-thirds 
of its length, the internal [submedian] nervure, from which it is separated 
by an interval about equal to the diameter of the nervure itself. Beyond 
this point the mane, gradually diminishing the radius of its curve, turns 
forward (that is, towards the dorsal [costal] edge of the wing) terminating 
at a little distance from the first branch of the median. Towards the base 
of the wing the hairs of the mane (PI. E, Fig. 5) are straight, and about 
3 mm. long ; in the middle 12-16 mm.; towards the apex about 8 mm., and 
blunt at their free extremities. At the spot where the mane turns away 
from the internal nervure the hairs are thicker, being about 6 mm. long, 
and bent into a slight curve with its convexity towards the base and inner 
margin of the wing. 
The hairs are not disposed in a single row, but, as may be best seen by 
their points of insertion, in 3, 4, or 5 layers, the number rising to 10 or 
more in the first two millimetres nearest the base of the wing. When the 
mane is removed, that part of the wing which lay beneath does not show 
any perceptible difference from the surrounding parts, yet microscopic 
examination reveals a profound distinction in the arrangement and form 
of the scales. 
The ordinary scales of the parts surrounding the organ (PL E, Fig. 10) 
are disposed in regular rows, made up of lower, or succubi, alternating with 
upper, or incubi. The distance between the rows is about 0*08 mm., that 
between the scales in the row about 0*03 mm. The upper scales, or incubi 
(Fig. 10 a) are longer (0*2), narrower (0'03), and at the same time darker ; 
the lower, or succubi (Fig. 10 h) shorter (0T3), broader (0*05), and paler ; 
but their apices are either rounded, like those of the incubi, or dentate. 
1 “ Obtuse angle ” is obscure. The submedian makes an acute angle with the 
median in both sexes.—E.B.P. 
