122 SYRPHID XE. 
halteres yellow. Abdomen black, punctate, with short, sparse, 
silvery pubescence; first segment entirely black, as broad as the 
scutellum; second greatly constricted in the middle, black, with a 
vellowish pellucid streak on each side, leaving in the centre a thin 
black median line, which is dilated into a triangle behind, the yellow 
streaks being therefore abbreviated forwards and reaching the hind 
border on the sides; third segment black, reddish towards the 
hind border, where there is a transverse band of silvery pubescence ; 
fourth entirely dark reddish, longer than the third, with a broad 
black spot on each side at the base; genitalia red, concealed ; belly 
red. Legs short and thin; coxe and femora black, the two 
anterior pairs partly reddish, the hind pair with yellow knees ; 

Fig. 20.—Microdon illucens, sp. N., a. 
Abdomen, x 9. 
four anterior tibie reddish, with white pubescence; hind tibie 
white on the basal, black on the apical half; all the tarsi reddish 
yellow, with a small black spot on the underside of each joint ; 
claws with black tips; hind tarsi not dilated. Wings hyaline, 
rather narrow, without stigma and with normal black veins; the 
two apical cross-veins and the well-developed stump are all pa allel ; 
lower corner of the subapical cell with short appendix, that of the 
diseal cell with none. 
Type 3, a single specimen from Cape Ceira, Mozambique, 
Portuguese Hast Africa, 3. vi. 1904 (4. Muir). 
Group II. (brevicornis, Loew). 
This group is composed of short rounded species, with short 
antenne and emarginate scutellum; they are not very different 
from the typical species and have the thorax and seutellum similarly 
