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UNITED STATES NATIONAL MUSEUM BULLETIN 2 24 



pleuron, and the posterior margin of the mesonotum 

 and the scutellar margin, are brownish yellow. In the 

 middle of the mesonotum are 2 or 3 blackish hairs 

 mixed in with the light colored hairs of the dorso- 

 central rows. Halteres long and quite large and red- 

 dish brown. 



Legs: The hind femur is about oy 2 times as long as 

 the middle femur, gradually and distinctly swollen 

 towards the apex; the long, hind tibia is even more 

 strongly swollen distally, the basitarsus quite swollen 

 and as long as the next 3 segments. Hind legs light, 

 reddish brown, a little more yellowish towards the base 

 of the femur and tibia. The coarse, appressed, setate 

 pile is brownish yellow. Only the apex of the tibia 

 with blackish bristles ventrally. Anterior and middle 

 legs brownish yellow, both of the tibia with a light 

 brown, ventral stripe and each femur with a shining 

 brownish spot on each side of the apex. 



Wings : The wings are unusually long and slender, 

 light reddish brown, paler in the middle of the posterior 

 cells. Stalk of anal cell and basal stalk of fourth pos- 

 terior cell unusually long. The oblique, anterior cross 

 vein enters the discal cell a little beyond the outer 

 fourth and the third vein forks well beyond the end of 

 the discal cell. 



Abdomen : The abdomen is brownish black in ground 

 color across the middles of the tergites but densely 

 obscured by fine, brownish ochre pollen or micro- 

 pubescence. Along the sides of the abdomen the 

 ground color changes to light, reddish brown, the pollen 

 shining and pale brownish yellow. Pile very scanty, 

 minute, appressed, and golden. Terminalia shining 

 yellowish brown, the epandrium is ventral in position, 

 with a long, upturned process on each side. 



Type: Male, Willow Grange, Natal. Collected by 

 R. C. Wroughton. Type in the British Museum 

 (Natural History) . Paratype male in the collection of 

 the author. 



Zygocolon, new subgenus 



Type of subgenus: Zygocolon compactus, new 

 species. 



Flies of less than medium size, with subclavate 

 abdomen and strongly humped mesonotum. Face, 

 antenna, and venation as in Damalis Fabricius, except 

 that the alula is more narrow. The proboscis is short 

 and rather stubby at apex, extending perhaps no farther 

 than the face and is directed downward. Lower half 

 of face with numerous, stiff hairs but no bristles. 



The postcoxal metasternum is extraordinarily devel- 

 oped, and extends forward as a long, rather flattened, 

 ventral plate that is curved laterally and ends beneath 

 the pronotum; in consequence all the legs are carried 

 forward and the three coxae lie in a nearly vertical 

 column behind the occiput. Hind trochanter consider- 

 ably elongate and the hind femur gently swollen 

 through the middle and bears on the distal half a 

 lateral row and a medial row of stout, sharp, subtuber- 

 culate spines on the ventral surface. Length 10 mm. 



Zygocolon compactus, new species 



Length 10 mm. Male. Head: The head is quite 

 short, wide and strongly flattened anteriorly. Ground 

 color is black on the vertex and front, thinly covered 

 with reddish sepia pollen, extending down to the trans- 

 verse, supraanteimal groove. The face and cheeks are 

 dark, shining brown, thinly overlaid with appressed, 

 brownish white, micropubescence, which is, perhaps, a 

 little darker on the upper half of the face. The upper 

 two-thirds of face quite fiat and below the face retreats 

 posteriorly. Fully the lower half of the face bears 

 numerous, brownish white, moderately long, stiffened 

 hairs but no bristles. Across the middle of the face 

 there is considerable short, whitish pile directed 

 upward. Proboscis blackish, rather bluntly pointed 

 and the quite small, short palpus blackish and composed 

 of 2 segments, with 5 long, slender, brown and yellow 

 bristles at the apex and some stiff, yellowish hail's at 

 the base of the first segment. Antenna brownish black, 

 the minute third segment somewhat more reddish, the 

 second segment pollinose with minute, apical setae, and 

 the first segment with a conspicuous, long, ventral, 

 blackish bristle. The ocelli prominent, set forward and 

 posteriorly, the ocellar tubercle bears a pair of rather 

 long, slender, blackish bristles curving forward. Ver- 

 tex with some fine, whitish pile and occiput margined 

 with a dense band of conspicuous, brownish white 

 pollen, rather narrow along the eye margins, giving 

 way to very thin, grey pollen or micropubescence over 

 the remainder of the occiput. Just inside the white, 

 lateral border is a row of slender, whitish, bristly hairs, 

 and medially more scattered hairs. 



Thorax: Mesonotum black with a faintly shining, 

 brassy lustre and changing to sepia brown laterally, 

 anteriorly, and in front of the scutellum. Pollen or 

 micropubescence of the mesonotum reddish sepia dor- 

 sally, changing to greyish white narrowly along the 

 sides and upon a distinct, narrow, transverse, prescutel- 

 lar band, which lies below the posterior apex of the 

 postalar callosity. The mesonotum has a double, acros- 

 tical row of moderately long, slender, black, bristly 

 hairs and dorsocentrally a more conspicuous row of 

 similar, bristly hairs longer posteriorly and changing 

 to white above the scutellum. Scutellum sepia, with 

 thin, white pubescence and on the margin a row of 4 

 or 5 pairs of slender, black, bristly hairs, the medial 

 pair being longer and more stout. Pleuron reddish 

 sepia, the pubescence with a yellowish tinge, and con- 

 tinued rather densely over the extraordinarily long, 

 postmetasternal, chitinized plate. Halteres large and 

 reddish brown. 



Legs : All the legs shining, light yellowish to reddish 

 brown with black, stiff pile and numerous, very slender, 

 long bristly black hairs, and with a scanty band of yel- 

 low hairs on the ventral surface of all of the femora. 

 These yellow hairs are longer on the first 4 femora and 

 extend around the anterior and posterior sides. Hind 

 femur with black, sharp spines ventrally on the outer 



