DAVIDINA. 157 



the fore-wings, apparently with a long gradually formed fusi- 

 form club; wings moderately broad, oval, rounded at the tips, 

 with long cells of nearly equal length ; hind-wings nearly as 

 long as the fore-wings. Costal nervure about two-thirds of the 

 length of the costa ; sub-costal nervure five-branched, the first 

 branch emitted just before the end of the cell, the second a 

 little beyond, nearly parallel to it, the third emitted a little 

 beyond it, and slightly diverging from it, the fourth and fifth 

 forming a rather large fork at the extremity of the wing. The 

 discoidal nervules both rise from the end of the cell, and from 

 the base of the median nervure rises a well-marked nervure in 

 the cell, which forks in the middle, the upper branch reaching 

 the end of the cell between the discoidal nervures, while the 

 lower one is continuous with the upper median nervule. 

 Hind-wings with a similar forked nervure in the cell, and ap- 

 parently with three sub-median nervures, the two lowest con- 

 fluent for a short distance from the base. 



It is not quite clear whether the forked cellular nervure and 

 the third sub median nervure are true or false. If perfect, the 

 structure is very remarkable ; if false, we meet with a well- 

 marked false third sub-median nervure in most of the allied 

 genera of Pieridce, and sometimes with obsolete traces of neura- 

 tion in the cell. In certain families of Moths (Zeuzerida, &c.) 

 the cell is still divided by nervures ; but, with the possible ex- 

 ception of Davidina^ this character has become almost obsolete 

 in Butterflies. 



DAVIDINA ARMANDI. 



Davidina armandi, Oberthiir, Etudes d'Ent. iv. pp. 19, 108, 

 pi. 2. fig. i (1879); Leech, Butterflies of China, p. 474, 

 Pi- 33, % 9(1893)- 

 The Butterfly measures about two and a quarter inches across 



the wings, which are yellowish-white, suffused with blackish 



