268 Orthorrhapha brachycera. 



F. A. I, 93 {Tachydromia). — 1903. Kat. palaarkt. Dipt. II, 276. — Musca 

 cimicoides: 1781. Fabr. Spec. Ins. II, 447,61. — Tachydromia cimicoides : 

 1805. Fabr. Syst. Antl. 144, 4. — 1862. Schin. F. A. I, 93. 



Male. Frons and vertex black, shining: palpi whitish haired, with 

 a black bristle at the apex. Occiput black, shining, with a few black 

 bristles above. Antennæ yellow, the third joint and the arista blackish 

 or brown. Thorax black, shining, a little æneous, with very short, 

 black hairs. A notopleural and a postalar bristle present, both black. 

 Scutellum with four black marginal bristles. Pleura black shining; 

 the propleural part whitish grey pruinose, so that there is a triangular, 

 whitish grey spot above the front coxæ. Abdomen black, shining, 

 with short, brownish hairs. Venter similarly coloured, the hairs longer 

 and darker. Legs yellow; the front coxæ whitish pruinose anteriorly, 

 the posterior coxæ black or brown ; the anterior feniora more or less 

 blackish or brownish above and at the apex, the tibiæ, except the 

 base, blackish; hind legs except the base of the tibiæ, and sometimes 

 also of the femora, black or blackish; the last tarsal joints blackish. 

 The front femora somewhat, the middle femora slightly thickened. 

 The legs are short-haired with pale hairs, on the postero-ventral side 

 of the hind femora a few longer hairs; the anterior femora with the 



Fig. 122. Wing of T. arrogans. 



ordinary rows of short spines below. Wings hyaline, with two broad, 

 blackish bands. Veins dark brown; the radial vein distant from the 

 margin, curved almost rectangularly upwards at the apex. Halteres 

 white. 



Female. With exception of the pointed abdomen quite similar 

 to the male. 



Length 2,2 — 2,7 mm. 



T. arrogans is a very common species in Denmark, generally 

 occurring on stems and on boards and walls, but also in herbage, 

 generally on humid ground ; vicinity of Copenhagen, Amager, Ørholm, 

 Nordskoven at Jægerspris, Rørvig and at Skelskør; on Langeland at 

 Lohals; on Funen at Hoffmansgave and Strib; in Jutland at Sminge 

 near Silkeborg, Gjerlev near Randers Fjord, Hald near Viborg and at 

 Bangsbo near Frederikshavn. My dates are ^^Ig—^^Is. 



