Lepidoptera from the White Nile. 157 
ocellation and other characters, though there is an extreme 
erocale-form in which they are lost. The “dry-season ” 
form C. catilla, Cram., which is probably strongly cryptic, 
belongs solely to the female sex. 
Pyrisitia proterpia, Fabr. Central and South America. 
This is a wet-season form of which there is every reason 
to suppose that P. gundlachia, Poey, is the dry-season 
modification, The seasonal changes of this species afford 
an interesting parallel with those in the genus /recis 
which have lately been so completely dealt with by Mr. 
Marshall and Professor Poulton.* The cryptic under-side 
of the dry phase is rendered still. more leaf-like by the 
uncination of the fore-wing and the prolongation of the 
hind-wing into a tail-like process, as in Precis archesia and 
P. antilope. This applies to both sexes, but is better marked 
in the female, as can be seen in the specimens figured (PI. 
VII, figs. 1-4). In the wet season both sexes have lost their 
leaf-like contour, but the female remains of a duller hue than 
the male. A somewhat similar case is that of Zeracolus 
auxo, Lue., both sexes of which in the dry-season form (7 
topha, Waller., or 7. keiskamma, Trim.) often show a slight 
uncination in the fore-wing, though in this species “ tails” 
are not developed. The cryptic colouring of the dry-season 
under-side is to some extent retained by the wet-season 
female (Pl. VII, figs. 5-8). 
This latter is a common feature in the African and 
Indian genus Zeracolus. T. phlegyas, Butl., T. ione, Godt., 
T. regina, Trim., 7. danae, Fabr., 7. eucharis, Fabr., 7. eris, 
Klug, are all cases in point, for in each of them the wet- 
season female shows beneath at least a trace of the 
characteristic dry-season tinge. Even where this does not 
occur, the under-side of the female in the wet season is 
usually more cryptic than that of the male, as may be 
seen, ¢.g., in 7’. omphale, Godt., and 7. achine, Cram. 
In Teracolus phisadia, Godt., and 7’. puellaris, Butl. (Pl. 
VII, figs. 9-12, 13-16) the principle receives perhaps its 
highest development. The female of the latter species 
retains its cryptic sand-coloured under-side at all seasons, 
the under-side of the male in the wet season being bright 
yellow. In the former species the female is always, on the 
under-side, a cryptic, sand-coloured, “ dry-season” form ; 
the male in the dry season may be similarly cryptic, or 
* See Trans. Ent. Soe. Lond., 1902, pp. 424 et sequ., Pl. XII, XIII. 
TRANS. ENT. SOC. LOND. 1903. II. (JUNE) Il 
