THYRIDIDAE OF AFRICA AND ITS ISLANDS 129 



very reduced signa in the bursa. At present no comparable differences have been 

 found in the male genitalia. Since the presence of the two thorn-like signa in the 

 bursa is very characteristic, this species is at present not divided into subspecies, 

 but is divided into groups of specimens based on the size and shape of the structures 

 in the female bursa. The following groups are obtained: 



(a) Nigeria, Democratic Republic of the Congo, [Dungu], Kenya. Two long 



thorn-like spines in bursa. 



(b) Malawi, S. Africa, Rhodesia, SW. Africa. Shorter spines in bursa, often 



with more teeth on them. 



(c) Nigeria, Zambia, Angola, Democratic Republic of the Congo [Elisabethville]. 



Bursa spines small, duct of bursa more sclerotized than in groups (a) and 

 (b), specimens smaller in size than those in groups (a), (b) or (d). 



(d) Ethiopia. Minute pairs of spines on sclerotized plate in bursa, duct 



sclerotized as in group (a). 



(e) Sudan, Ghana. Thorn-like spines in bursa, duct highly modified. 



With the overlap in distribution between these groups, none is a clearly distinct 

 subspecies. More material in each group is needed to establish the relationship of 

 the different groups, and information on the biology, none of which is available at 

 present, would help. In group (e) (perhaps even a distinct species) the large sclero- 

 tized development round the ostium is the only difference between that specimen and 

 specimens in group (c). While the differences between some of these groups are as 

 large as the differences between species in other genera, the general morphology of 

 all specimens at present included in curvifluus is very similar. 



With the relatively small amount of material available from any one locality, I 

 do not think that naming these groups would serve any useful purpose. H. curvifluus 

 can be identified from the characters given and, in particular, is characterized by the 

 signa of the female. Externally H. curvifluus is very similar to H. striatalis Swinhoe 

 from India, but these two species can be separated by the shape of the basal process 

 on the valve of the male and in the female by the signum. 



Distribution (all groups). Map 53. Ghana; Nigeria; Democratic Republic of 

 the Congo ; Ethiopia ; Sudan ; Kenya ; Tanzania ; Burundi ; Malawi ; Zambia ; Rhodesia ; 

 Angola; South West Africa; South Africa. 



Material examined. 



Holotype $, Nigeria: Warri (Roth), vi.[i8]o,7, BM slide no. 9584, in BMNH. 



Ghana: i $, Kete-Krachi, N. Territories (Cardinall); Nigeria: i $, Agberi, Niger, 

 vii.1901 (Ansorge); 1 $, N. Nigeria (Cator); Democratic Republic of the Congo: 

 2 (J, 1 $, Elisabethville, xi.1932-ix.1934 (Seydel), one <J, one $ in MRAC; Ethiopia: 

 1 $, Dire Daoua, iv.1936 (Uhlenhuth); Sudan: i $, Roseires-Ingessorna Hills, xi.1939 

 (Snow); 1 ct, Fung Prov., Kurmuk, iv.1929 (Disney); Kenya: i <J, Kitale, iv.1962 

 (Dougall), in NMK; Tanzania: i $, Kilossa, i.1922 (Lovendge) ; Zambia: i $, Nkama, 

 xi.1933 (Prismall), in TMP; 1 <$, Bwana Mkubwa, ix.1929 (Marley), in TMP; 

 Rhodesia: 1^,1$, Bulawayo, ix-x.1953 (Pinhey); 1 <$, Wankie, xi.1961 (Weir), in 

 NMR; 1 $, Hillside, x. 1922 (Swi nburn & Stevenson) , in TMP ; 1 $, Khami.nr Bulawayo, 



