4 6 P. E. S. WHALLEY 



with which it shares a number of characters (broad valve with median process, 

 aedeagus with lateral process). The female of Neochrysotypus is unknown but will 

 probably have a highly modified anal papilla if the generic relationship with 

 Chrysotypus is correct. Only two species of Neochrysotypus are known and the 

 genus is restricted to the mainland of Africa. 



Generic description. Proboscis reduced. Antennae ciliate or minutely ciliate. Labial 

 palps with three segments. Fore wing with R i +R i coming off common stem of i? 8 + 

 R 4 +R 5 . Fore tibia with epiphysis. Hind tibia with two pairs of spurs. Tarsi without spines. 

 Uncus simple. Gnathus lightly sclerotized or absent. Transtilla and base of costal margin 

 of valve highly modified. Aedeagus with lateral process. Valve broad, with median process 

 in more subapical position. 



$. Unknown. 



Biology : No information. 



Key to African species of NEOCHRYSOTYPUS 



I Fore and hind wings with distinct reticulate pattern (PI. 4, fig. 10). Male genitalia 

 with narrow median process on valve and slender posterior projection of transtilla 

 (PI. 27, fig. 143) ........ cerussus (p. 46) 



- Fore and hind wings with distinct transverse markings but not strongly reticulate. 

 (PL 23, fig. 121) Male genitalia with broad median process on valve and broad 

 posterior extensions of transtilla (PI. 27, fig. 145) . . . mysticus (p. 47) 



Neochrysotypus cerussus sp. n. 



(PI. 4, fig. 10; PI. 27, fig. 143) 



o\ Wing, 14-5 mm. Vertex white. Antennae minutely ciliate. Frons flattened between 

 eyes. Proboscis small. Labial palps upturned, not reaching vertex, third segment 1/3 length 

 of second. Thorax white. Hind tibia with two pairs of spurs. One spur of proximal pair 

 very reduced, not visible through scales. Fore wing, pattern as in PI. 4, fig. 10, translucent 

 white with brown reticulations and brown mark over apex of cell. Underside similar. Veins 

 i? 4 and i? 5 joined, coming off common stalk of i?g+i? 4 +i? 5 , vein R 2 approaches closely and in 

 places touches this common stalk. Hind wing, colour and pattern as fore wing. Conspicuous 

 brown spot at apex of cell. Veins 5c+i? x and Rs free. 



Genitalia^ (PI- 27, fig. 143). Uncus short, blunt-ended. Gnathus absent. Valves broad, 

 median process on each valve clavate, reaching almost to apex of valve. Basal part of valve 

 strongly sclerotized and toothed. Basal part of costal margin of valve and transtilla highly 

 modified, extending posteriorly into two strongly sclerotized, pointed arms. Juxta, two lightly 

 sclerotized lobes. Aedeagus distinctly bifid, manica minutely spined. 



§. Unknown. 



Discussion. The two specimens of this species, collected at the same time, 

 differ in intensity of the dark reticulation. The second specimen also differs from 

 the holotype in having both proximal spurs on the hind tibia weU developed. The 

 most remarkable structure in the male genitalia is the enormous development of the 

 transtilla. This, at first sight, looks like a modified gnathus but is clearly from the 

 transtilla. Although this is an unusual modification it is also found in Neochry- 

 sotypus mysticus. Most of the other morphological structures are similar to the 

 more typical Chrysotypids. Externally this species is similar to N. nivosa but can 



