258 Dr. Frederick A. Dixey on the 
and Ganoris. Indications of the series, more or less pro- 
nounced, can also be seen in H. timnatha, H. aspasia, 
H. judith, H. nama, and other species. 
The strong resemblance to WDelias belladonna borne 
by Prioneris thestylis is very probably due to mimicry, 
as suggested by Wallace (“ Pieride of the Indian and 
Australian Regions,” Trans. Ent. Soc. Lond., 5rd series, 
iv., pp. 309, 383). But from the presence of traces of the 
submarginal series in other species of Prioneris (as in P. 
autothisbe and P. clemanthe), it seems likely that it is 
rather the retention than the origin of the submarginal 
series in P. thestylis that is attributable to this cause. 
Material for the production of a likeness of D. belladonna 
was no doubt already to hand in the existence of an 
homologous series of markings in both insects. Other 
species of Prioneris, not having the same reason for 
keeping close to the original design, have strayed away 
more or less widely from it. 
Mr. Wallace has also pointed out the agreement in 
some respects between Delias and the South American 
genus Huterpe (ibid., p. 344). If, with Mr. Butler, we 
divide Swainson’s genus Huterpe into Pereute, Leodonta, 
Catasticta and Huterpe proper, we shall find that while 
all the normally coloured species of the group are 
demonstrably linked with one another and with Delias 
by their general system of marking and scheme of 
coloration, two of the genera (Pereute and Leodonta) 
further suggest a near relationship with Delias by the 
peculiarities of their neuration; there being in these 
instances only three instead of four subcostal nervules 
in the forewing (Butler, “ Revision of the Genera of 
the Subfamily Pierine,’ Cistula HEntomologica, vol. 1, 
1870, pp. 39, 40, ete). The appearance of several 
species of this group of genera (notably Huterpe tereas) 
has been profoundly altered by mimicry; but putting 
aside such forms as these, we shall find no difficulty 
in tracing a common pattern throughout most of the 
remaining members of the group. ‘This pattern is not 
dissimilar from that which characterizes those species of 
Delias which we have seen to be probably the older 
(e.g., D. belladonna, D. pasithoe and D. thisbe). To this 
part of the subject I shall return later, at present it will 
be sufficient to point out the distinct presence of the 
submarginal series S in such examples as Catasticta 
