80 



Orthorrhapha brachyceia. 



Tahle of Species. 



1 . The spine-like bristles on the tibiæ black ; sixth and seventh 



abdominal segments in the male steel-blue 1. cyanurus. 



— The spine-like bristles on the posterior side of the front 

 tibiæ and on the anterior and posterior sides of the middle 

 tibiæ yellow; sixth and seventh abdominal segments in 

 the male not steel-blue 2. cothurnatus. 



1. N. cyanurus Low. 



1849. Low, Linn. Entom. IV, 84, 49, (Itamus) — 1862. Schin. F. A. 

 I, 155, (Asilus). — 1903. Kat. palåarkt. Dipt. II, 155. — 1842. Asilus 

 aestivus Zett. Dipt. Scand. I, 167, 3, p.p. et 1855. XII, 4561, 3. 



Male. Eyes in the living specimens greenish, slightly metallic. 

 Face yellow or greyish white; epistomal beard black above, yellow 

 or white below. Palpi black with black and whitish hairs. Frons 

 and vertex dark grey with black hairs. Occiput grey, the occipito- 

 orbital bristles black, curved strongly forwards; the hairs white. 

 Antennæ black, the two first joints black haired, the hairs below 

 somewhat long. Thorax grey, ash-grey or nearly bluish grey behind ; 

 the stripes blackish, the middle stripe with a distinct median line; the 

 side stripes large, distinctly divided into three spots. The disc clothed 

 with longish, erect, black hairs which are longer behind; the bristles 

 black, the dorsocentral rows continued a little beyond the middle. 

 ScLitellum with erect, pale hairs and black marginal bristles. Pleura 

 grey pruinose with longer, yellowish hairs; the long hairs on meta- 

 and hypopleura yellow. Abdomen blackish; with the light from be- 

 hind slightly [shining with light grey hind margins of the segments 

 and the anterior corners of the second segment of the same colour; 

 the three last segments somewhat narrowed, steel-blue, shining. Venter 

 grey, the three last segments shining black. Abdomen clothed with 

 somewhat longish, yellow hairs, along the middle line the hairs are 

 black; the hairs are long at the side margins of the anterior segments; 



at the hind margins of the segments 

 there are pale bristles which are short 

 along the middle, long towards the 

 sides. Venter sparingly clothed with 

 long, yellowish hairs. Genitalia large, 

 black; the arms of the upper forceps 



broad, rounded at the apex ; the lower 

 Fig. 31. N. cyanurus, male forceps. e i u- u li? iu i 4.u 



^ ' ^ forceps only reachmg halt the length 



of the upper, the inner branch longer than the outer, crescent-shaped 



with a convex lower and a concave upper edge; the ventral lamella 



black, shining; the genitalia clothed with longish, black hairs. Legs 



