Afiican Species of the Genus C'lirysops. 509 



a fifth specimen from the shore of Lake Victoria, in Buddu, 

 1903 (S/eepinr/ Sickness Commission of the Royal Society, 

 per Colonel David Bruce, C.B., R.A.M.i'., F.R.S.). 



Of the Afiican species already clescribecl, Chrysops funehris 

 appears, so far as may be judged from the description, most 

 nearly to resemble C. conjlHens, Lw., from the Cape of (jood 

 Hope, from which, however, it may at once be distinguished 

 by the slender anteunie, single frontal callus, and very 

 different wing-markings. 



Chrysops silacea, sp. n. 



? . — Length (17 specimens) 8 to 10 mm. ; width of liead 

 2f^ to 3 mm. ; width of front 1 mm.; length of wing 7^ to 

 Q\ mm. 



Head yellow ; thorax black or blackish brown, with yellow 

 longitudinal stripes ; scutellum ochre-yellow, median portion 

 of extreme base black ; abdomen ochraceous, upper side marked 

 on basal half icith two lonyitudinal black stripes, not reaching 

 hind margin of third segment, and sometimes not extending 

 beyond second ; distal portion of wing from base of third vein 

 infuscated, transverse band inconspicuous, reduced to a small 

 dark blotch e.vfenduig from base of third vein to posterior 

 upper angle of fifth posterior cell; legs ochraceous, front tarsi 

 and tips of middle and hind tarsi dark brown. 



Head rather broad, dark brown on vertex, elsewhere 

 clothed with ochre-yellow pollen, except on frontal callus, a 

 mark above base of each antenna, the facial tubercles, and 

 a small dark brown spot on the jowls below each eye ; frontal 

 callus of moderate size, three fourths as w'uXc as the front 

 and well separated from tlie eye on each side, not highly 

 polished, edged with brown at the sides or sometimes all 

 round the upper curved margin ; facial tubercles highly 

 polished, elliptical in shape, occupying lower two tiiirds of 

 face and extending nearly to margin of buccal cavity, 

 separated from each other by a narrow stripe of yellow 

 pollen ; often only the upper portion of the pollinose stripe 

 is present, when the tubercles coalesce below and assume 

 tlie ajjpearanee of a single elongate cordate tnberele, which 

 extends to the lower margin of the face ; front, except on 

 callus, clothed with short brown hair, densest on vertex ; 

 sides of face and lower surface of head clothed with pale 

 golden hair ; palpi lanceolate, widest part of moderate 

 breadth, thinly clothed with minute yellowish hairs ; 

 antemue 3| mm. in length, dark brown, basal portion of 

 slender Hrst joint tawny ochraceous. Thin-ar clothed with 



