876 REPORT OF THE HARVARD AFRICAN EXPEDITION 
biting a native on the shore of Lake Nyasa shortly after sunset (1912, Bull. 
Ent. Res., III, p. 285) and of Schouteden’s capture of 7’. stimulans after dusk. 
Since 7’. concinna is likely to be found in Katanga, it has been included in 
my key. 
Tabanocella perpulcra (Austen) 
Rhinomyza perpulcra Austen, 1910, Ann. Mag. Nat. Hist., (8) VI, p. 349 (9; Kasala Stream near 
Mpumu, Uganda). 
This species has also been recorded from the Kavirondo District of Kenya 
Colony, the fauna of which is West African. Some years ago I saw a female 
from Medje, Belgian Congo (H. Lang and J. P. Chapin), which at the time 
seemed to be J’. perpulcra; but the specimen is no longer available, so that 
the occurrence of this species in our territory remains doubtful. 
Thriambeutes Grinberg 
Thriambeutes Griinberg, 1906, Zool. Anzeiger, XXX, p. 352. Monotypic for Thriambeutes singularis 
Griinberg, 1906. Enderlein, 1925, Mitt. Zool. Mus. Berlin, XI, 2, pp. 306 and 309. 
In a recent paper (1927, Amer. Mus. Novitates, No. 285, pp. 1-4), Hine 
has attempted to show that the characters assigned to Thriambeutes, Orgi- 
zomyia and Guyona are more properly specific than generic. I am strongly 
inclined to the same view. However, since no specimens of either Pangonia 
mesembrinoides or Pangonia zigzag are available, I shall provisionally treat the 
three genera as distinct. The only characters that seem at all reliable have 
been given in the key. It will be noted that Guyona is transitional between 
Orgizomyia and Thriambeutes, combining the broad, toothed third antennal 
segment of the former with the stout palpi of the latter. 
The genus is exclusively Ethiopian and known by three species. Two of 
these occur in the Belgian Congo and may be separated as follows: 
1. Both sexes colored alike. Head and thorax coal black; abdomen bright ferruginous 
red. Antennae, palpi and fore legs black; middle and hind legs ferruginous red, 
the middle femora infuscated. Wings uniformly very dark smoky. Length, 10 to 
IG EI is Be ec oeer io cie ep Seven 9s oe BEA Soe aME. RNP DORE at ERT te T. austent. 
The two sexes differently colored. Female: head, antennae, palpi and thorax bright 
ferruginous red; abdomen and legs coal black. Male: entirely ferruginous and 
covered with golden yellow pubescence, except the legs which are black. Wings 
infuscated, with hyaline spots and bands as follows: a spot at the base of the 
wing; a narrow, oblique cross-band just before the discal cell extending from the 
first longitudinal vein to the hind margin; a small round spot in the basal half of 
thediscal cell. The apical third of the wing beyond the discal cell is hyaline except 
for a narrow smoky band along the anterior margin reaching the tip of the wing 
and separated from the main brown area on the costa. Length, 11.5 to 13 mm. 
ei iop F Seas ge iye RaU RSP ese se 8 nT ys 2 i LaPR ails Wo viavscl aby Veo Whey bya Vel Je eae ee T. singularis. 
Thriambeutes austeni (Hine) 
Orgizomyia austent Hine, 1927, Amer. Mus. Novitates, No. 285, p. 3 (9 #; Stanleyville, Belgian 
Congo). 
This species is known only from the type locality where numerous speci- 
mens were taken as prey of Bembix bequaerti Arnold var. dira Arnold. 
