926 REPORT OF THE HARVARD AFRICAN EXPEDITION 
and connected very faintly along the hind margin with smaller spots in the 
hind corners. The fore tibiae bear very little white pile basally. Hyaline 
areas of the wing very sharply defined, the median clear band extending well 
into the fourth posterior cell. 
Surcouf’s description and figures differ rather markedly from the insect 
figured by Austen and represent the insect from the Belgian Congo which I 
describe below as var. congoicola. Surcouf states that the female type came 
from ‘West Africa” (collected by L. Conradt and in the Madrid Museum; 
therefore almost certainly obtained in Spanish Guinea or Rio Muni). But he 
also had before him, in drawing up his description, two other females from the 
Belgian Congo (one without more definite locality, the other from Bena Bendi). 
Since Austen states expressly that his figure was prepared from the type, the 
West African form, as represented in Liberia, should be regarded as the typl- 
cal marmorosus. 
T. marmorosus is strictly West African, being known from Sierra Leone, 
Liberia, the Gold Coast, Southern Nigeria, Cameroon, Spanish Guinea, Uganda, 
and (in the var. congoicola) the Belgian Congo. Its supposed occurrence in 
Tanganyika Territory (Austen, 1926, Ark. f. Zool., XVIII B, No. 6, p. 2) is 
based upon a misapprehension; the specimen in question came from the Ituri 
District, Belgian Congo.1 
Tabanus marmorosus var. congoicola, new variety 
Female. — Length, 19 to 22 mm.; width of head, 7 to 7.5 mm.; length of wing, 18 to 20 mm. 
A lighter form of 7. marmorosus, with which it agrees in most respects. Dorsum of thorax 
lighter, the ground color often shading into reddish brown, and more abundantly covered with 
grayish tomentum; the scutellum with few black hairs basally. The first and second abdominal 
tergites are mostly slate-gray and covered with silvery white pubescence; the second with an oval 
or crescent-shaped, median, black area, covered with black pile, and with similar black areas on 
each side in the extreme corners; the three following tergites each with a low, more or less triangular, 
median, white spot on the hind margin; the spot of the fourth tergite the largest and rather broadly 
connected along the hind margin with the conspicuous white hind corners. Fore tibiae with an 
appreciable amount of silvery white pile basally. Hyaline areas of wing less sharply defined, the 
median clear band scarcely entering the fourth posterior cell. 
Male. — Length, 21 mm.; width of head, 7 mm.; length of wing, 17 mm. 
Head large and hemispherical; eyes bare, contiguous; area of enlarged facets extensive, en- 
circled by small facets; antennae, proboscis, and palpi black; triangle of vertex very small, pale 
brown in color; frontal triangle normal, extreme upper angle dark brown, remainder gray pollinose 
with a narrow brown collar around the insertion of each antenna; face gray pollinose and pilose; 
beard white. Dorsum of thorax grayish brown and clothed with long, fine, white hairs; scutellum 
white. Abdomen: first tergite mostly dark brown, with a posterior gray margin; the second 
gray with a rounded, mid-dorsal, dark brown spot closer to the anterior than to the posterior margin: 
the third dark brown, with a wide, posterior, gray margin which is widest on mid-dorsal line; 
the fourth similar, but the gray posterior margin more extensive; the fifth similar, but the eray 
posterior margin very much reduced; the remaining tergites entirely dark brown; ventrally, 
first sternite pale brown; the second largely pale brown, but with three large, nearly black spots, one 
1 In this 1926 paper, Austen reports a number of tabanids from ‘‘Tanganyika Territory, Ituru 
District.’’ These insects were obtained by Gyldenstolpe during Prince Wilhelm of Sweden’s Expedition 
to the eastern Belgian Congo, which did not enter Tanganyika Territory. There can be no doubt that the 
locality meant was the Ituri District, Belgian Congo, a region with a typical West African fauna. More- 
over, I have not been able to locate an “Ituru District” on any of the maps of Tanganyika Territory in 
my possession and Mr. Arthur Loveridge tells me he has never heard of it. ; 
