Species of the Genus Lwienitis. 457 



marks in and on the costal side of the base of the cell are 

 retained, and, lightened in tint, represent the two more 

 conspicuous white spots occupying nearly the same position 

 in Anosia. 



These changes, together with the transformation of a 

 dark chocolate-brown ground-colour into a pale yellowish 

 tint are the means by which the hind-wing under surface 

 of the non-mimetic ancestral arthcmis has become that of 

 its beautifully-mimetic descendant, archippus. 



b. Fore-v)ing Under Surface of Limenitis archippus. — The 

 changes on the under surface of the fore-wing must now 

 be considered. In artliemis the angulated black line, 

 bordering the outer edge of the white discal band, runs 

 from the costa to the anal angle of the wing. In archippus 

 its anal extremity has been shifted upwards until it 

 now joins the hind margin about at the junction of its 

 middle and anal thirds. Rendered far more conspicuous 

 against the ground-colour, greatly expanded at its costal 

 end and there enclosing from two to four white spots, 

 vestiges of the outer part of the white band, the marking 

 now adds greatly to the mimetic resemblance, by its like- 

 ness to the subapical pale-spotted black band of Anosia. 

 A further trace of the white band is generally seen on the 

 costa itself, here often persisting for a distance equal to 

 the normal width of the marking in arthcmis. This 

 cliaracter has also probably been retained because of its 

 resemblance to the costal white markings of Anosia. 



The two deep reddish patches in the cell of arthcmis 

 have disappeared in archippus, converted, with the ground- 

 colour around them, into a fulvous tint considerably darker, 

 as in the model, than that of the hind-wing and the apical 

 region of the fore. Between these red patches in arthemis 

 is a variable bluish triangular mark often pupilled with 

 white and often surrounded by a black border. Other 

 even more variable markings of the same kind are seen in 

 the base of the cell. Although the red spots have dis- 

 appeared in archippus the outer of these pale marks is, 

 together with its black margin, almost always retained of 

 full size but whiter than in arthemis. A trace of the basal 

 mark or marks is also generally to be seen, sometimes only 

 in the form of the black margin including a few pale bluish 

 scales. This feature persists in a more complete state in 

 the female specimens I have had the opportunity of ex- 

 amining. The outermost triangular pale mark, in spite 



