Bombyliidae. 113 



base. Squamulæ blackish, yellovvish fringed; frenulum with yellow 

 hairs. Halteres blackish brown, the knob somewhat paler. 



Female. Quite agreeing with the male, only the frons slightly 

 broader. 



Length 8—8,5 mm. 



This species is of a somewhat more slender shape than most 

 other species; the above description is made from four Danish speci- 

 mens, one male and three females which are all quite similar. It 

 agrees also rather well with Low's description 1. c; Low describes 

 the halteres with a white knob, this may probably be so in fresh 

 specimens. 



A. occultus is very rare in Denmark, only four specimens have 

 been caught, all in Jutland; Frijsenborg (H. I. Hansen) and in the 

 vicinity of Silkeborg (A. Petersen); the dates are in July and to ^"^/s. 



Geographical distribution: — Middle Europe down into Germany, 

 it seems to have its northern limit in Denmark; the species seems on 

 the whole to be somewhat rare. 



5. A. circumdatus Meig. 



1820. Meig. Syst. Beschr. II, 143, 2. — 1842. Zett. Dipt. Scand. I, 

 196, 2 et 1849. VIII, 2980, 2. — 1903. Kat. palåarkt. Dipt. II, 175. — 

 1862. A. hottentottus Schin. F. A. I, 51. 



Male. Black; frons with short, erect, black hairs, and with some 

 depressed, yellow hairs, especially on the anterior part; epistoma and 

 jowls with yellow hairs, in the middle of epistoma a few black hairs; 

 occiput with silvery, above and backwards more golden hairs, a short, 

 whitish fringe at the hind margin. Antennæ black, the two first 

 joints black haired ; the third joint tapering into a long styliform part. 

 Thorax more or less covered with black, shining, scaly hairs, behind 

 with short, depressed, yellow hairs over a part almost triangular 

 with the base towards the scutellum; the middle part of the disc is 

 clothed with erect, blackish hairs; in front they are more dense and 

 yellow, forming at the front end the common fringe; there are yellow 

 hairs along the lateral margins and likewise, but less dense, in front 

 of the scutellum. Pleura with long, yellow hairs, specially dense 

 above; on the metapleura a vertical tuft of yellow hairs. Scutellum 

 covered wMth black scales, and with depressed yellow hairs at the hind 

 margin. The postalar bristles yellow, the marginal scutellar bristles 

 partly black, partly yellow. Abdomen with the ground colour black, 

 at the sides on the first and second segments a reddish spot; the 

 dorsal surface is covered with black scaly hairs; at the front margin 

 of the second, third and fourth segments and at the hind margin of 



Diptera Danica. IL 8 



