Thelaira. 547 



flat behind and almost not puffed out below, considerably higher 

 than long. Frons in male somewhat narrow, in female broader, 

 widening downwards, almost not protruding. Jowls narrow. In both 

 sexes ocellar and inner vertical bristles and in female two orbitals, 

 the uppermost placed high above. Postocular bristles fme, with no 

 black hairs behind. Fine postocellar and occipital bristles. Frontal 

 bristles not reaching to end of second antennal joint, all crossing 

 in male, in female a very small outwards directed bristle may be 

 present above. Cheeks bare. Vibrissæ slightly ascending. Oral bristles 

 strong, directed forwards. Eyes bare. Epistoma somewhat retreating. 

 Oral cone and proboscis short, labella rather large; clypeus short, 

 horse-shoe-shaped. Palpi somewhat long. Antennæ inserted below 

 middle of the eye, second joint short, dilated apically with the anterior 

 corner protruding, third linear, twice to thrice as long as second; 

 arista plumose, second joint short. Thorax rectangular; three post- 

 sutural dorsocentrals and three præ- and postsutural acrostichals ; 

 no præsutural intraalar bristle. Scutellum with three marginal bristles 

 on each side, the apical crossing. Two sternopleural bristles. Ptero- 

 pleura above with a bundle of hairs but no bristle. Abdomen elongated 

 conical; excavation on second segment not reaching hind margin; 

 there are discai and marginal bristles, second segment with a pair 

 of marginal; fifth segment with discai and marginal bristles. Legs 

 long, especially tarsi long with long joints; claws and pulvilli in male 

 strongly elongated. Wings with first posterior cell open, ending a 

 little before apex of wing; discai angle almost rectangular, but the 

 angle itself may be rounded; subcostal and cubital vein with bristles, 

 on the latter stretching towards medial cross-vein; no costal spine. 



The species is parasitic on Heterocera and belongs to Pantel's 

 group 6. 



Of the genus only one species is known, also occurring in Denmark. 



1. T. nigripes Fabr. 



1794. Fabr. Ent. Syst. IV, 319, 30 et 1805. Syst. Antl. 293, 47 [Mitsca). 

 — 1826. Meig. Syst. Beschr. V, 38, 8 et 1838. VII, 270, 3 {Dexia). — 1896. 

 Pand. Rev. Entom. XV, 148. — 1899. Brauer, Sitzungsber. Acad. Wiss. Wien, 

 C VIII, 506, 35. — 1907. Kat. palåarkt. Dipt. III, 435. — 1921. Baer, Zeitschr. 

 f. angew. Ent. VII, 378. — 1924. Stein, Arch. f. Naturgesch. 90, 6, 153. — 

 Musca leuæzona Panz. 1809. Faun. germ. CIV, 19. — 1826. Meig. 1. c. V, 37, 7 

 et 1838. VII, 270, 1 {Dexia). — 1844. Zett. Dipt. Scand. III, 1266, 4 et 1849. 

 VIII, 3263, 4 et 1859. XIII, 6173, 4 {Dexia). — 1862. Schin. F. A. I, 555. — 



35* 



