ADAMS : DIPTKRA AFRICANA. 189 



OSCINID^. 



Crassiseta. 



(Von Roser, Verz. Wurtt. Dipt. Nachtrag ; 1840.) 



Crassiseta tarda, n. sp. 



Front, including the triangle, yellow, ocellar dot blackish, on 

 sides and in front with yellowish, bristle-like hairs, frontal tri- 

 angle subshining, reach two-thirds way to the antennie ; face 

 yellow, slightly excavated, and with a low median carina, 

 vibrissse present ; cheeks narrow, yellow, in certain lights sil- 

 very, occiput yellow, two submedian, brownish marks above 

 neck ; antennae yellow, narrow upper border of the third joint, 

 and arista black, arista not so prominently thickened as in most 

 species of Crassiseta; mouth-parts yellow. Thorax reddish 

 yellow, largely shining, short pile yellow, two bristles in front 

 base of wing and two above black, scutellum with four small 

 tubercles, each bearing a bristle, halteres yellow. Abdomen 

 shining brownish black, venter at base in one specimen yellow- 

 ish. Legs wholly yellow. Wings hyaline, third section of 

 costa a little shorter than the second. Length, 2 mm. 



Two specimens ; May. This is very close to C. flavida Will., 

 from St, Vincent, W. I. The arista is shorter than in flavida, 

 and the frontal triangle is much shorter and less shining ; other- 

 wise they are very similar. 



Crassiseta scapularis, n. sp. 



Front opaque brown on upper half, yellow on lower, bristly 

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

 two-thirds way to antennae, face and cheeks yellow, grayish 

 pollinose, former 'nearly plane, vibrissa? present, occiput black 

 above, yellow below, antenm^ yellow, arista black, mouth-parts 

 yellow. Thorax black, humeri and line in front of base of wing 

 yellowish, mesouotum, scutellum, and pleurse above thinly 

 grayish pubescent, one humeral, two posthumeral, and two 

 supraalar bristles present, scutellum with a minute apical pair 

 of tubercles, from which arise a pair of bristles, a smaller bris- 

 tle on each side, halteres yellow. Abdomen subshining black, 

 venter yellowish. Legs light yellow, front tarsi and tip of fol- 

 lowing pairs black. Wings hyaline, second and third sections 

 of costa of equal length. Length, 1.8 mm. 



Two specimens ; April. 



