ADAMS : DIPTERA AFRICANA. ISl 



Wings hyaline, with a grayish tinge, veins brownish black, 

 second section of costa a little longer than third, small cross- 

 vein nearer to base of third vein than to hind cross-vein. 

 Length, 2 mm. 



Crassiseta tuberculata, n. sp. 



Front opaque black, yellowish on anterior part, small bristly 

 hairs on sides and in front, triangle shining black, reaches 

 four-fifths way to antennae, with a pubescent stripe passing di- 

 agonally from ocelli to center of each side ; cheeks narrow, 

 black, grayish pubescent ; occiput black ; antennoe yellow, 

 arista black, longer than usual, acuminate ; mouth-parts brown- 

 ish black. Thorax black, two posthumeral and two supraalar 

 bristles, mesonotum, scutellum and upper part of pleurae uni- 

 formly grayish pubescent, scutellum with four prominent 

 tubercles, each bearing a rather strong bristle, halteres yellow. 

 First twQ segments of abdomen yellowish above and below% 

 with their lateral margins black, following segments shining 

 black. Legs yellow, middle and hind femora toward apex, and 

 tip of tarsi brownish. Wings hyaline, second section of costa 

 slightly longer than the third. Length, 2.2 mm. 



One specimen ; October. 



Crassiseta vulgaris, n. sp. 



Front opaque yellow below, brownish above, orbits somewhat 

 grayish, a row of short black bristles on each side reaching 

 almost to antenniie, other small black hairs on anterior part, 

 triangle shining black, reaching two-thirds to antennae, ocellar 

 dot grayish pubescent ; face excavated, blackish, a pair of 

 vibrissse present ; cheeks narrow, yellow, oral margin slightly 

 projecting; occiput black above, yellow below; antennse yel- 

 low, upper side of third joint and arista black ; proboscis black- 

 ish, palpi yellow. Thorax black, largely shining, mesonotum 

 and scutellum with a uniform thin coat of grayish pubescence ; 

 two posthumeral and two supraalar bristles present ; scutellum 

 non-tuberculate, with one pair of large and a small pair of 

 bristles ; halteres yellowish white. Abdomen black, subopaque, 

 venter sometimes yellowish at base. Legs largely yellowish, 

 the femora and hind tibite sometimes brownish, tips of tarsi 

 blackish. Wings hyaline, veins dark brown, second section of 

 costa a little longer than the third, small cross- vein nearer to 



