ADAMS : DIPTERA AFRICANA. 195 



black, the four anterior knees, tips of all tibise, and tarsi yel- 

 low. Wings as in the preceding species. Length, 3.25 mm. 

 Numerous specimens ; October. 



Pachylophus varipes, n. sp. 



Front broader than one of the eyes, short, scarcely projecting 

 in front of the eyes, yellowish on the anterior margin and lower 

 half on the sides, the silvery hair-like line along the orbits 

 scarcely visible, absent in some specimens, a few minute black 

 hairs on sides and in front, triangle long and slender, plane, 

 shining black ; face straight, forming with the front an angle 

 of about ninety degrees, oral margin not projecting, brownish 

 black ; cheeks narrow, with a yellowish cast, covered with 

 grayish pollen ; occiput black, grayish pollinose ; antennae 

 black, third joint yellow on the lower side, arista two-jointed ; 

 mouth-parts yellow. Thorax black, mesonotum and scutellum 

 uniformly gray pollinose, pleurne partly shining; halteres yel- 

 low. Abdomen black, subopaque, with a thin coat of dust. 

 Legs largely yellow, in some specimens the front and hind 

 femora are largely black, last joint of all tarsi black, hind femora 

 only moderately incrassate. Wings grayish hyaline, third and 

 fourth veins straight, gently divergent, second section of costa 

 shorter than the third. Length, 2.4 mm. 



Numerous specimens ; May. 



Pachylophus fossulata, n. sp. 



Front a little broader than one eye, not projecting, yellowish 

 on anterior margin and on lower half of sides, triangle shining 

 black, reaching nearly to the antennae, contiguous with the eyes 

 above, and containing two, sometimes one large one, small 

 fossae, one at apex and one near middle ; face nearly straight, 

 with a brownish-yellow cast, sides grayish pollinose ; cheeks 

 small, yellowish, gray pollinose ; occiput black, gray pollinose ; 

 mouth-parts yellow ; antennae largely yellow, upper margin 

 and apex of third joint, and arista, black, latter composed of 

 two joints. Thorax black ; mesonotum and scutellum finely 

 scrobiculate ; pleurae smooth, shining; halteres brownish, 

 knobs sometimes yellowish on inner side. Abdomen black, 

 dorsum of first two segments, sometimes the third also, more 

 or less of a yellowish cast. Coxae and legs yellow, front tibiae, 



4-Bull., Vol. Ill, No. 6. 



