i 9 6 D. S. FLETCHER 



iv. 1955, i $ (NMK, Nairobi); ibidem, xi. 1965 (R. H. Carcasson), 1^,1$ (NMK, 

 Nairobi); ibidem, iv, viii, xi (G. Pringle), 1 J, 2 $ (BMNH). 



The DIONE-Groxjp 



Externally similar in colour and pattern to species in the xystra-group. 



Characterized in the male genitalia by the slender, tapered uncus and absence 

 of ventral plate on the gnathus; by the form of the slender valve which bears long 

 setae from the lobate apex of the ventral margin and by the form of its dorsal 

 process which is angled through 90 degrees at mid-length. The aedeagus is 

 tapered, with a small thorn-like projection at one-half. The fulcrum is slender 

 with a scobinate apex. 



The male hind tibia is similar to those found in the metrioscaphes-gvoup, not 

 dilate but enclosing a capsule of short hair-scales. 



Only one species is known. 



Zamarada dione (Prout MS) sp. n. 

 (Text-figs 324, 325; PI. 118, fig. 1057) 



q (PI. 118, fig. 1057). Greenish tinged hyaline area striate with grey and finely edged 

 distally with black; discal spot on hind wing minute and black, that on fore wing light grey 

 outlined with black; costa of fore wing buff, irrorate with grey. Non-hyaline terminal area 

 brown (pi. 7, E5, Somalis) varyingly irrorate with grey; dentate subterminal fascia a redder 

 tone of brown. Underside of non-hyaline terminal area greyish brown, paler terminad. 



$ genitalia (Text-figs 324, 325). Juxta slender and bifurcate. Valve slender; ventral 

 apex lobate bearing long setae; dorsal process right-angled at mid-length with small, setose 

 projection near base. Coremata buff. 



$ unknown. 



Measurements. Fore wing: $ 19-20 mm. Antennal pectinations: J 5 X diameter of 

 shaft. 



Similar in colour and pattern to species in the xystra-group and to rupta sp. n. 

 in the principis-gvoup, but males may be distinguished by the simple hind tibia. 

 In the male genitalia the form of the valve is diagnostic. 



Distribution. Zaire, Gabon. 



Holotype J, Zaire ('Belgian Congo'): Middle Lowa Valley, Nr Walikali, 

 3-4000 ft, forest, ii. 1924, wet season (T. A. Barns), Geometridae genitalia slide 

 no. 6431, in BMNH. 



Paratypes. Zaire ('Belgian Congo') : holotype data, 1 <$; W. Kivu, South Lowa 

 Dist., Lowowo Valley, 4000 ft, mountain forest, hi. 1924, wet season (T. A. Barns), 

 1 $ (both BMNH). Gabon: Belinga, Camp Central, 700 m, 29.V.1963, 1 3; 

 Belinga, Piste de Mwadi, 800 m, 20.iii.1963, 1 <$; Belinga, N. Crete Sud, 1000 m, 

 19.iii.1963, 1 $ (all G. Bernardi, in MBG, Paris). 





