ENTOMOLOGY 919 
from St. George d’Elmina were the West African form here described from the 
Lower Congo and Senegal, for which van der Wulp’s name might be retained. 
Tabanus boueti Surcouf 
Tabanus boueti Surcouf, 1907, Bull. Mus. Hist. Nat. Paris, XIII, p. 333 (9; Lower Ivory Coast); 
1914, ‘Doc. Scientif. Miss. Tilho,’ III, pp. 343 and 344, Pl. III (Dipt.), figs. 3-4 ( ¢). 
BELGIAN Cone@o. — Stanleyville, 6 females and 4 males, taken as prey 
by Bembix bequaerti Arnold var. dira Arnold, March 1915 (H. Lang). 
The females of this series are black rather than blackish brown. 
Male (undescribed). — Length of body, 14 to 15 mm. ; 
Extremely similar to the female, but the abdomen is more chocolate brown, contrasting 
with the black thorax and head. The wings are smoky throughout, a little paler toward the apex 
and with indications of paler spots in the center of most of the cells. As usual, the head is consider- 
ably enlarged; the eyes meet broadly on the vertex and are composed of larger facets in the 
upper two-thirds. 
Four specimens from Stanleyville. 
T. boueti is known only from the Ivory Coast, Dahomey, and the Belgian 
Congo. 
Tabanus besti Surcouf 
Tabanus besti Surcouf, 1907, Archives de Parasitologie, XI, p. 473 (9; Gambia); 1909, ‘Et. 
Monogr. Taban. Afrique,’ pp. 46 and 55 (¢) (PIL. I, fig. 11, as bowett Surcouf?). 
Tabanus obscurissimus Ricardo, 1909, Ann. Mag. Nat. Hist., (8) I, p. 272 ( 9; Libreville, French 
Congo). Austen, 1909, ‘Illustr. African Blood-Suck. Flies,’ p. 73, Pl. V, fig. 387 (2). 
Liperia. — Moylakwelli, October 27, 1926. Kolobanu, October 29, 1926. 
Bomboma (Moala), October 31, 1926. Banga, October 1926. The eyes in life 
are uniformly purplish black. 
BELGIAN Coneo. — Stanleyville, females and males (Lang and Chapin). 
Lubutu; Walikale; Djambi; Penge. Makala (Christy). Lomami (J. Schwetz). 
Bandaie, Uele district (J. Rodhain). 
T. besti is a West African species extending from the Gambia to Uganda. In 
Liberia the typical form is much less abundant than the var. arbucklei Austen. 
After a careful study of an extensive series of specimens, I am unable to 
separate 7’. obscurissimus, of the Congo, from T’.. bestv, of West Africa proper. 
I believe that Surcouf was justified in regarding them as identical. The extent 
of the white, basal band of the fore tibiae is variable and the middle and hind 
tibiae may be reddish brown to black. 
Male (undescribed). — Length of body, 15 to 18 mm.; width of head, nearly 6 mm.; length 
of wing, 11 mm. 
Colored like the female, but the basal, narrow, white ring of the fore tibiae appears to be less 
marked. Head large. Eyes holoptic; area of large facets extensive, entirely encircled by small 
facets; band of small facets narrowed at vertex, of about uniform width along the hind margin 
of the eye nearly to the outer inferior curvature, where it widens rapidly for some distance and 
then narrows toward the frontal triangle. Third segment of antenna decidedly narrower than in 
the female. 
I have seen several males from Stanleyville, collected by Mr. H. Lang. Together with some 
females of the same species, they were being carried as prey to the nest by the fossorial wasp 
Bembix bequaerti Arnold var. dira Arnold. 
