Therevidae. 141 



quite as the preceding, the eighth is shining black. Venter with long, 

 pale hairs on the three first segments, and with short, erect, yellow 

 hairs on the rest. Legs as in the male, but the hairs on the femora 

 shorter. 



The species may vary somewhat in eolour especially in the male, 

 this being sometimes quite ashgrey and the hairs then being very pale. 



Length 7,5—10,5 mm. 



This species is easily known by the quite unicolorous abdomen, 

 and in the female by the seventh segment being of the same eolour 

 as the other abdominal segments and not black. 



T. suhfasciata is not rare in Denmark; Hornbæk, Tisvilde, Ods- 

 herred; on Falster at Stubbekøbing; in Jutland at Ribe, Søndervig 

 and Frederikshavn. My dates are '^^\i — ^^/s. It occurs on sandy piaces 

 on or near the shore. I caught it especially on Urtica urens, often 

 in great numbers. 



Geographical distribution: — Northern and middle Europe down 

 into Fi'ance; towards the north to southern Scandinavia. 



Remarks: This species v^as found in the coUection of foreign 

 Diptera in our Museum under the name hybrida Loew, with locality 

 Posen, sent by Loew to Stæger, but Loew has then evidently changed 

 the name before publication. 



± T. nobilitata Fahr. 



1775. Fabr. Syst. Entom. 757, 5 (Bibio) et 1805. Syst. Antl. 67, 7 



(Bibio). — 1842. Zett. Dipt. Scand. I, 203, 1 et 1849. VIII, 2982, 1. - 



1847. Loew, Dipt. Beitr. II, 7, 4. - 1862. Schin. F. A. I, 164. — 1903. 

 Kat. palåarkt. Dipt. II, 209. 



Male. Frons and face yellowish pruinose; the hairs on the frons 

 chiefly black, above the antennæ more or less intermingled with yel- 

 low; the black hairs continuing downwards along the eye-margin to 

 the jowls; for the rest the hairs on the face yellow. Occiput with 

 yellow hairs, the occipito-orbital bristles black ; the hairs on the vertex 

 black. Antennæ black, the first joint yellowish or greyish pruinose; 

 the first two joints with black hairs, intermingled with some yellow. 

 Thorax yellowish brown or darker brown, with two brighter yellow 

 stripes; the disc somewhat sparingly clothed with erect, black hairs, 

 and more densely with decumbent, yellow hairs. There are generally 

 two dorsocentral bristles, sometimes four and then the anterior gene- 

 rally weaker than the postorior. Pleura and sterna grey with yellow 

 hairs which may be more or less pale. Abdomen black, the first 

 segment almost all yellowish; at the hind part of the following seg- 

 ments a broad, yellowish, transverse band which is narrow in the 



