274 Dr. Frederick A. Dixey on the 
also in the hindwing. I propose to designate the system 
as D 1—5.* 
The last-named genera exhibit a good deal of varia- 
tion in the size of the constituent spots of D, and 
also in the breadth of the encircling darker ring. In 
C. catilla $, the latter, spreading widely out from the 
silver centres, and being reinforced in the hindwing 
by a similar development from certain of the spots of 
series S, forms a conspicuous dark red patch on the 
under surface of both primaries and secondaries. A 
similar tendency is seen in many specimens of Callidryas 
thalestris and other members of that genus. In all these 
cases the border of the discoidal spots on the under 
surface is assimilated in colour to the general character 
of the darker mottlings that form the prevailing feature 
of the wing-pattern. It is interesting to observe, in the 
case of Phebis trite, that the straight diagonal streak 
already referred to (p. 260) as crossing the under surface 
of the hindwing is made up of elements belonging to 
both series S and D, as follows: The part between the 
two subcostal nervules is S 14; that between the sub- 
costal and discoidal is D3; the next, where the streak 
intersects the second disco-cellular, is D 4; it then skips 
a space, and reappears between the median and sub- 
median nervures as § 19. That the homology of the 
different parts of this line has been correctly stated will 
be evident from a comparison of P. trite with C. eubule 
and C, thalestris, in which species the elements of the 
streak are visible in a separate condition. It is in P. 
trite particularly worthy of note that in those interspaces 
where D 3 and 4 form part of the streak, the corre- 
sponding members of §, viz., S 15, 16, and 17 (which 
are not wanted for this purpose), are visible well to the 
outer side of the streak; whereas in the other inter- 
spaces there are no marks between the streak and the 
margin, the members of S having been, so to speak, 
used up for another purpose, and having thus caused an 
apparent interruption of the usual submarginal pattern. 
In the interspace between the first and second median 
“ This use of D is open to the objection that the same letter 
has also been used for an entirely different set of markings in the 
Nymphalidz (see Trans. Ent. Soc. Lond., 1890, p. 91). But I do 
not think that this circumstance is likely to give rise to any 
practical difficulty. 
