LIST OF DIPTERA. 347 



with pale yellow bristles in front, and with more pale yellow hairs 

 beneath : eyes piceous, divided into two regions by the difference in 

 size of the facets ; the first part, composed of large facets, is flat, 

 and occupies the crown ; the second part, composed of small facets, 

 is much larger than the first, which it half encircles : mouth tawny, 

 piceous at the tip, a little longer than the head : feelers tawny ; 

 first and second joints beset with black bristles ; second joint a little 

 longer than the first; third joint piceous, spindle-shaped, tawny at 

 the base, a little longer than the first and the second joints ; fourth 

 joint piceous, conical, very small : chest with two indistinct dark 

 stripes and having four rows of black bristles, two of them on the 

 stripes, and two ou each side, where the chest is paler : breast tawny : 

 abdomen cylindrical, shining, rather darker towards the base, and 

 slightly decreasing in breadth from thence to the tip : legs tawny, 

 beset with hairs and bristles of the same colour : wings tawny, espe- 

 cially along the borders of the veins ; fore borders very slightly con- 

 vex ; wing-ribs and veins ferruginous ; poisers tawny. Length of 

 the body 6 lines ; of the wings 10 lines. 



a. ? 



Dasypogon Sergius, n. s. Ferrugineus, thorace nigro bivittato, ab- 

 dominis fasciis duabus mediis nigris, antennis ferrugineis, pedi- 

 bus fulvis, alis limpidis ad cos tarn subfulvis. 



Body ferruginous, thinly clothed above with tawny hairs : head 

 thickly clothed behind and beneath with yellow hairs ; crown pi- 

 ceous ; front covered with close shining tawny down ; clypeus armed 

 with eight long pale yellow bristles : eyes black, the front part flat 

 and composed of larger facets, but the difference in point of size 

 is not so conspicuous as in many other species : lip short, stout, pi- 

 ceous, tawny at the base, ferruginous and covered with a cluster of 

 yellow hairs at the tip : feelers ferruginous ; first and second joints 

 beset with tawny hairs ; second joint much shorter than the first ; 

 third joint nearly linear, longer than the first and the second joints ; 

 fourth joint small, shorter than the second ; fifth joint extremely 

 small : fore chest short, its disk mostly black : two broad black stripes 

 on the chest : breast and sides of the chest partly covered with shining 

 yellow down, the latter beset with pale yellow bristles : abdomen 

 nearly cylindrical, thinly clothed with very short yellow hairs, much 

 narrower than the chest and more than twice its length, its breadth 

 decreasing from the base to the fourth segment, and thence slightly 

 increasing to the tip ; first segment extremely short ; second segment 

 piceous, short, broad, convex, beset on each side with long yellow 

 hairs ; third segment long, with two broad black stripes along its 

 whole length, having a cross suture and a cross row of punctures 



