GERYDUS. 28i 



strongly curved at base, thence bisinuate to termination at apex 

 of wing. Antennae a little less than half length of fore wing, 

 club slender, very gradual ; palpi slender, scaled, not fringed 

 anteriorly, third joint long ; eyes naked ; thorax and abdomen 

 elongate, <5 with a subanal tuft of stiff hairs ; legs abnormal, 

 compressed, the first joint of the tarsi remarkably long, flattened 

 and broad ; claws minute. Some forms of the genus have, in the 

 males, a conspicuous sex-mark, that consists of a slight thickening 

 of the basal portion of vein 4 on the upperside of the fore wing. 

 Of the Indian forms the following have this sex-mark: 

 G. symethus, G. ancon, G. boisduvali, G. longeana, G. biggsii, and 

 G. irroratus. G. croton only is without it. 



Key to the forms of Gerydus. 



A. Upperside hind wing: a patch or broad 



streak beyond apex of cell white or whitish, 

 conspicuously paler than ground-colour 

 of wmg . G. symethus, p. 290. 



B. Upperside hind wing : ground-colour more 



uniform, no conspicuous white or pale 

 patch or streak beyond apex of cell. 



a. Upperside fore wing : basal half white, 



suffused at base with dark or pale brown, 

 with a longitudinal broad brown streak 

 extended into the white area. 

 '. The white area completely divided by 



the brown streak G. ancon, p. 291. 



V. The white area not completely divided 



by the brown streak G. lonyeana $ , p. 293. 



b. Upperside fore wing : basal half of some 



shade of brown, not white, 

 o'. Upperside fore wing : with a more or 

 less conspicuous discal oblique white 

 fascia. 

 a 2 . This fascia curved, interrupted and 



macular posteriorly. 

 3 . Of comparatively large size, ex- 

 panse over 40 mm G. croton, p. 294. 



i 3 . Smaller, expanse under 40 mm. 

 <t l . c? $ Upperside fore wing : 

 macular, discal white fascia 

 narrow, lower spots composing 

 it well separated ; basal area of 

 wing not conspicuously paler 



than apical area G. boisduvali, p. 292. 



b 1 . c?. Upperside fore wing: ma- 

 cular, discal white fascia broad, 

 lower spots composing it not 

 well separated; basal area of 

 wing conspicuously paler than 



apical area G. lonyeana tf , p. 293. 



b 2 . Discal fascia not curved, not macular, 



straight, broadest in middle G. bit/gsti, p. 295. 



b'. Upperside fore wing : without a discal 

 fascia, only a white spot beyond apex 



of cell G. irroratus, p. 295. 



VOL. II. U 



