CHBYSOGASTER. 17 



distinct spots ; antennas inserted below the middle of the eyes, 

 moderately short, dark yellowish brown ; third joint as long as 

 twice the first two joints together, narrow, rounded at the tip ; 

 arista long, quite bare. Thorax practically bare, with only a few 

 short pule hairs on the sides of the back ; dull blackish seneous, 

 black on the pleurae, where is to be seen a little grey tomenturn ; 

 back without pattern, faintly striped, coarsely punctate. Scutellum 

 large, quadrangular, margined, like the thorax; its exceedingly 

 short hairs are inserted in distinct punctures. Plumulae and 

 squamulae white, the thoracic one with a long white fringe ; halteres 

 yellowish. Abdomen broad, flattened, and margined, the last seg- 

 ment rounded; almost bare, its exceedingly short pubescence 

 inserted in punctures, which on the sides are very coarse ; the sides 

 are shining aeneous, with a purple band on posterior margin of 

 second and third segments; on the back the first segment is black, 



Fig. 4. Chrysogaster spiloptera, pp. n. $. X 6. 



except at the sides, the second and third show a very broad velvety 

 black band, which does not reach the sides, but is triangularly 

 produced forwards, touching with its apex the hind border of the 

 preceding segment ; fourth segment almost entirely shining, with 

 only a small black triangle in middle of fore border, emarginate 

 behind. Venter shining black. Legs entirely black, short and robust, 

 almost bare ; basal joints of front and hind tarsi thickened, chiefly 

 those of hind pair. Wings hyaline, yellowish towards the base and 

 with yellowish stigma; the marginal cell contains two rounded brown 

 spots near its end ; there are also two apical cross-bands, one beginning 

 in the submarginal cell, just before the end of the marginal cell, 

 and united with the dark border on the subapical cross-vein ; the 

 other is less dark, placed just before the tip of the wing, crossing 

 the marginal cell and the outer part of the first posterior cell ; besides 

 there are brown elongate cloudy patches in the middle of the sub- 

 marginal cell, in the subapical cell, and in the discoidal cell. Sub- 

 apical cross-vein recurrent. 



Type $, a single specimen from Obuasi, Ashanti, l.ix.1907, 

 "caught in swamp'* (Dr. 7P. 3f. Graham}. 



c 



