Bombylidae (Diptera) from Central Africa. 607 
2. Bombylius ornatus, Wiedemann (1828). 
Fifteen specimens of both sexes of this common African 
species, Songwe River, North Nyasa, June 21,1909; near 
mouth of River Rumpi, May 12, 1909; Mwenetete village, 
Songwe River, June 21, 1909, round cattle (Qh zeae 
Florence Bay, November 1, 1909; Deep Bay, October 31, 
1909; Marimba, Ukasi village, ’ January 15, T9390 (all 
from Dr. J. B. Davey) Mzimba West Nyasa, May and 
June 1909 (Dr. H. S. Stannus). 
2. Systoechus, Loew (1855). 
This genus, which is of economic importance, is well 
represented in the collection by numerous specimens 
belonging to five different species. The larvae live in the 
egg-cases of locusts, as observed in N. America by Riley 
(S. oreas preying on Oedipoda atrox) and in Europe by 
Stepanoff, Schimkewitch and Portschinsky (S. autwmnalis 
and leucophaeus on Stawronotus maroccanus). 
The species before me can be distinguished as follows :— 
1 (2). Femora wholly black ; abdomen with very few black bristles; 
wings tinged at the base with dark brown or blackish. 
albidus, Loew. 
2 (1). Femora wholly yellow or black at the base only ; abdomen 
with or without bristles; wings wholly clear or wich a 
brownish or yellowish tinge at the base. 
3 (6). Abdomen without black bristles at the hind margin of the 
segments ; femora wholly yellow. 
4 (5). Eyes of the male separated; face with yellow hairs; hind 
femora with black spines; wings broadly infuscated at 
the base . , : . vobustus, sp. n. 
5 (4). Eyes of the male ioncane : ised with black hairs ; hind 
femora with yellow spines ; wings clear at the base. 
simplex, Loew. 
6 (3). Abdomen with black bristles at the hind margin of the 
segments. 
7 (8). Face with black hairs ; hind femora with yellow bristles 
melampogon, Sp. Dov. 
8 (7). Face with yellow hairs ; hind femora with black bristles 
ctenopterus, Mikau. 
3. Systoechus albidus, Loew (1860). 
The abdomen of this species bears very few black 
bristles, the most of these being whitish. I think that 
