70 Dr. F. A. Dixey on the phylogenetic 
Ancestral marks produced at high temperatures (A). 
(1). The presence of a scarlet patch on the under | 
surface of the fore wing between the first median nervule 
and submedian nervure (in two specimens). 
(2). The increased width of the scarlet band on the 
fore wing, and the tendency in some cases of its inner 
margin towards resolution. 
(83). The somewhat diminished intensity of the scarlet 
of the fore wing. 
(4). The suffusion of the dark portion of the wings 
with golden brown. 
In all these respects the specimens of A approach 
P. callirrhoé, which is, in my view, an older and less 
specialised form than V. atalanta (Trans. Ent. Soe. 
Lond., 1890, p. 128, and note). The scarlet patch (1) is 
undoubtedly identical with a light-coloured area, between 
the spots distinguished as Il. 8 and III. 8, which is met 
with on both surfaces of P. callirrhoé, and is present in 
a more ample form in other members of the group 
(ibid., Pl. IlI., figs. 88, 40, 41, representing V. poly- 
chloros, A. levana, and P. carye respectively). 
Ancestral marks produced at low temperatures (C and D). 
(1). The presence, in some specimens, of blue or 
lavender centres to the black submarginal spots of the 
hind wings. 
(2). The presence, in two specimens, of minute groups 
of blue scales near the margin of the dark portion of 
the hind wing, indicating the centres of another series 
of spots (the series distinguished as III., well seen in 
G. c-aureum and P. gonerilla, ibid., Pl. I., fig. 25). 
(3). The presence, in two specimens, of marginal blue 
on the hind wing. 
With regard to (1), it is clear that the tendency is 
for the blue centring to increase as the temperature 
diminishes. Thus (to use the system of nomenclature 
proposed by the writer, loc. cit.) IV. 15 is, of course, 
universally blue-centred ; IV. 14 is blue-centred in one 
of A, five of B, eight of C, and all of D; moreover, five 
of the seven specimens comprising the latter group have 
blue centres to other members of IV. as well. The 
remarkable specimen of D figured (fig. 5) has IV. 12 to 
