Lepidopfcra from tJir White Nile. 157 



ocellation and other characters, though there is an extreme 

 CQ'Ocale-ioxva in which they are lost. The " dry-season " 

 form C. eatilla, Gram., which is probably strongly cryptic, 

 belongs solely to the female sex. 



Pyrisitia jJrotcrjna, Fabr. Central and South America. 

 This is a wet-season form of which there is every reason 

 to suppose that F. gundlacliia, Poey, is the dry-season 

 modification. The seasonal changes of this species aftord 

 an interesting parallel with those in the genus Precis 

 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-wiDg and the proloDgation of the 

 hind-wing into a tail-like process, as in Precis archcsia and 

 P. antilopc. This applies to both sexes, but is better marked 

 in the female, as can be seen in the specimens figured (PL 

 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 Teracolus 

 auxo, Luc, both sexes of which in the dry-season form {T. 

 to'pha, Wallgr., or T. Iceislcamma, 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 Teracohis. T. phlegyas, ButL, T. ione, Godt., 

 T. reginn, Trim., T. danac, Fabr., T.e'acJiaris,¥ahY., T. 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, c. g., in T. omphcde, Godt., and T. achine, Cram. 



In Teracolus pMsadia, Godt., and T. puellao'is, ButL (PL 

 VII, figs. 9-12, 13-16) the principle receives perhaps its 

 highest development. The female of the latter species 

 retains its cryptic sancl-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 tlie 

 under-side, a cryptic, sand-coloured, " dry-season " form ; 

 the male in the dry season may be similarly cryptic, or 



* See Trans. Ent. Soc. Lond., 1902, pp. 424ef seg-n., PI. XII, XIII. 

 TRANS. ENT. SOC. LOND. 1903.— PART II. ( JUNE) 11 



