thyrididae of africa and its islands 153 



Material examined. 



Holotype $, Uganda: Ankole, Kalinzu Forest, xi.1961 (Carcasson), BM slide no. 

 10599, in BMNH. 

 Paratype. Uganda: i <$, data as type. 



Nemea betousalis (Gaede) comb. n. 



(PI. 18, figs 95, 96; PL 43, fig. 242; PL 64, figs 405, 406) 



Rhodoneura betousalis Gaede, 191 7 : 376. 

 Rhodoneura bryaxis Fawcett, 191 7 : 246, syn. n. 

 Rhodoneura betousalis Gaede; Gaede, 1929 : 494. 

 Rhodoneura bryaxis Fawcett; Gaede, 1929 : 494. 



o*. Wing, 11 mm. Vertex and frons brown. Antennae ciliate. Labial palps upturned, 

 just reaching vertex, third segment 1/2 length of second. Prothorax pale brown, rest of thorax 

 white. Hind tibia with outer spur 1/2 length of inner spur. Fore wing, pattern as in PI. 18, 

 rig- 95. white with brown reticulate pattern. Basal area brown. Several black spots between 

 veins subapically. Costal margin slightly concave, fringe brown. Underside colour and 

 pattern as upperside. Hind wing, colour as fore wing but basal area white. Median black 

 spot in cell on brown median fascia. Underside, as upperside. Sc+Ri and Rs free. 



Genitalia <J (PI. 43, fig. 242). Uncus simple, broad at base, gradually narrowing. Gnathus 

 present with small median projection. Valve simple. Median basal process of valve well 

 developed and sclerotized with spiny pad on base of valve, anterior to basal process. Juxta, 

 two lateral lobes with hairs on a slightly thickened basal plate. Saccus elongate. Aedeagus 

 with manica toothed on one side and small spines over rest of manica. 



$. Wing, 11*5-13 mm. Vertex and frons brown. Antennae minutely ciliate. Labial 

 palp upturned, just reaching vertex, third segment 1/2 length of second. Legs as male. Fore 

 wing, pattern as in PI. 18, fig. 96, brown with broad, dark brown, median fascia reaching from 

 hind margin of cell. Rest of pattern as male. Hind wing pattern as male, median brown fascia 

 right across wing. Black spot on median fascia prominent. Underside, as upperside. Vena- 

 tion as in male. 



Genitalia $ (PI. 64, figs 405, 406). Anal papillae short. Ostium broad, covered with small 

 spines. Duct of bursa strongly spined. Signum absent. Bursa with a few spines. 



Discussion. The females of this species are much darker than the two males 

 examined. The females vary considerably in intensity of colour, particularly of 

 the dark patch on the wing. The male specimens lack most of the antennal segments 

 but the basal segments are more strongly ciliate than the female. This species has 

 very distinctive male genitalia and seems to be most closely allied to the eugrapha- 

 nivosa species-group. It can be separated from these by colour and genitalic 

 differences but the rest of the morphology is similar. N. betousalis is unusual amongst 

 the African Thyrididae in having such strong sexual dimorphism of colour and 

 pattern. In spite of widespread collecting no specimens have been taken outside 

 Kenya. Until more males are collected, there is a small element of doubt of the 

 correctness of the association of the males and females of this species. 



Distribution. Map 69. Kenya. 



Material examined. 



Holotype $ (betousalis), Kenya: Kibwezi (Scheffler), BM slide no. 9703, in ZMB. 



LECTOTYPE $ (bryaxis), here designated, Kenya: B.E. Africa, Kedai, 26.xi.1911 



