Aphiochaeta. 377 



short. Thorax black, slightly shining, with brownish pubescence^ 

 about the humeri it may be a little reddish. Mesopleura bare. Ab- 

 domen somewhat slender as in rufipes^ black, a little greyish, dull; 

 the sixtli segment is rather elongated; the short hairs a little longer 

 at the hind margins of the segments ; abdomen is clothed as in rufipes 

 with long hairs on the sides, but the hairs are relatively longer and less 

 dense; on first and second segments there are no long hairs. Hypo- 

 pygium medium-sized, of common shape; it has on the sides an about 

 vertical row of hairs similar to those on abdomen; anal tube short, 

 but somewhat stout, yellow or yellowish. Legs yellowish or light 

 brownish yellow, the hind legs the darker; the hairs below the basal 

 half of hind femora long; hind tibiæ of a curious shape, the dorsal 

 hair-seam has, a little above the lower third, a sudden and strong 

 deflection towards the anterior, and an elongated triangular area 

 behind it is flattened, so that it looks as if the dorsal edge here wa& 

 cut off; on the upper part of the tibiæ there are four or five fme, hair- 

 like bristles; the apical spur on middle tibiæ rather long, almost a& 

 long as metatarsus. Wings slightly yellowish tinged, veins yellow; 

 costa not reaching to the middle, 1 about double 2 and longer than 

 2 + 3; costal cilia long, but not specially long; fourth vein evenly 

 curved and only slightly more in its first part. Halteres yellow. 



Female. Unknown. 



Length 1,3 to fully 1,5 mm. 



Of this interesting species only one specimen, Wood's type, 

 was hitherto known; it does not seem to be extraordinarily rare in 

 Denmark, Dr. Mortensen has taken no less than 16 specimens in 

 Holte from V? to Vs in 1917 to 1920; they were taken on windows, 

 but the species is no indoor form, it came, as many other species, 

 casually on the windows in his villa at the wood. Further I have 

 myself taken a specimen at Hejls south of Kolding ^^/t 1919 and one 

 at Ry ^^Z? 1918; both the latter specimens were taken with the net 

 in low herbage in woods. 



Geographical distribution: — Besides from Denmark only known 

 from England. 



120. A. albidohalteris Felt. 



1896. Felt, 12th Rep. State Eiit. New York, 228 {Phora). — 1903. Brues,. 

 Trans. Arner. Ent. Soc. XXIX, 368. — 1910. Kertész, Cat. Dipt. VII, 404. — 

 1912. Malloch, Proceed. U. S. Nat. Mus. 43, 496. — 1914. Brues, BuU. Wisc. 

 Nat. Hist. Soc. XII, 111. — Phora derasa Wood, 1909. Ent. Month. Mag. 2,. 

 XX, 194, 243. — Aphiochaeta derasa 1914. Wood, 1. c. 2, XXV, 154. 



