30 
Thus, in the case of imagines in flight, by observations from a tree 
or from a hole in the ground, or from underneath such herbage as they 
frequent, and especially of imagines at rest from below, much sugges¬ 
tive material of which we are ignorant might be acquired. 
It is hoped at least that these few remarks will justify the imagin¬ 
ing that our “ point ” opens up many lines of discussion. 
In suggesting a separate consideration of the opposite surfaces one 
can appeal to nature as doing the same herself. 
Even in such cases as L. avion, and some Polyommatids, where a 
median row of black spots traverses the coloured disc on both surfaces 
of the primaries, there is no necessary correlation. An alteration of 
shape or size of these spots on upperside, is not necessarily accom¬ 
panied by a similar condition on underside, or may be represented by 
a less extent of the same, e.y., striation. 
That this is so is noteworthy, inasmuch as this striate condition of 
spots of underside is a comparatively common condition in allied 
species. L. bellavyits, L. con/dan, L. icarus, in all of which a black 
spot on the upperside of primaries is extremely rare, or unknown in 
S s, the converse being true of L. avion. And in the J s of these 
species also, with exception of the discoidal spot, any black spots on 
upperside are extremely rare, whereas in L. avion, with its extremely 
uncommonly striate underside, striate forms of the upperside are 
abundantly common, or reach to an extreme degree. 
The lack of correlation, in any accurate degree, of upper- and 
underside markings in the case of L. avion, L. bellavgus, and P. plilaeas, 
are only special instances of a common condition in butterflies, viz., 
that where the markings of the upperside are (as it may be said) 
reproduced on the underside (or vice versa as it may be), the markings* 
seldom if ever exactly correspond, the limits on one surface are 
different from those on the other. 
Sometimes they would appear to have dropped on one surface, as 
I', cavil ui., where the upperside shows the extra-median spots of lower 
wing are nearer to the border than are the compound concentrically 
ringed ovals of the underside. 
In the J s of P. napi, P. rapae, etc., the black spots of the upper- 
wings are frequently (between the nervures and past the nervures) 
more extensive than on the underside. The white bands of L. sibylla, 
on the contrary, are narrower than the same on underside. 
In other species the markings have the appearance of having been 
pushed further away from bases of wings, and this in many (? all) 
species of a group. In C. pamphiliis, the apical spot of the upperwing 
on the upperside occupies principally the outer part of that area 
opposite the underside marking, and frequently extends beyond it. 
The same may be said of C. typlion, C. titlionm, K. ianira, etc.—of all 
in the upper wing. In the case of C. typlion var. rotliliebii, it is on 
the underside, on the contrary, that the ringed spots are nearer the 
margin than on the upperside of the hindwings. 
And in practically every species examined most specimens show 
analogous markings to be more extensive on one surface than on the 
other, i.e., they only partially overlap, e.g., pale lunules of margins of 
A. euphrouyne and A. selene, etc., on the underside, tend to be en¬ 
croached on by the surmounting dark crescents, and even the separat¬ 
ing nervures, less than on upperside. 
xix. 
