146 



A. WATSON 



Outer margin of hind wing evenly arcuate. Venation of fore wing as in Text-fig. 235 ; R t 

 arising from cell ; areole absent, R i stalked with i? 5 and not anastomosed with R 3 . Sc + i? t in 

 hind wing anastomoses for short distance with Rs distal to end of cell. Upper surface of fore 

 wing with weakly marked antemedial fascia ; two cell-spots ; oblique, well marked postmedial 

 fascia ; dark costal marking at about three-quarters distance from base to apex ; two closely 

 apposed dark spots near tornus, one on either side of vein \A . Upper surface of hind wing 

 sometimes with trace of antemedial fascia, continuous with postmedial fascia of fore wing ; other- 

 wise unmarked. Under surface of fore wing sometimes with weakly marked postmedial fascia ; 

 hind wing seldom with trace of antemedial fascia ; both fasciae corresponding exactly in 

 position with same fasciae on upper surface. (See Plate 17.) 

 genitalia. (See description of type-species.) 



Discussion. In external fades this genus closely resembles Oreta Walker 

 (1855 : 1166), type-species by subsequent designation (Kirby, 1892 : 728) Oreta 

 extensa Walker (1855 : 1166), except for the absence of cell-spots on hind wing. It 

 differs from Oreta in the following important respects : the fore wing of the female 

 is strongly falcate, more (not less) falcate than the male fore wing ; there is no 

 areole in the fore wing ; in the male genitalia the uncus is bifid and directed anteriorly, 

 the gnathus has no lateral arms, the diaphragma has become modified to form a 

 sclerotized pocket, and the eighth abdominal sternum is longer (antero-posteriorly) 

 than wide. This kind of sexual dimorphism in the shape of the fore wing together 

 with the form of the eighth sternite are characters shared with Spidia Butler. 



There is considerable individual variation in the coloration of the wings. 



The genus is monotypic and apparently confined to Madagascar. 



R, **-5*J R< 



Fig. 235, Oretopsis vohilava, 5* fore wing venation. 



