Aphiochaeta. 405 



black or blackish, of ordinary size and armature. Thorax black, a 

 little shining, with dark brownish pubescence. Mesopleiira bare. 

 Abdomen somewhat roubst, black, a little greyish and dull, the hind 

 margins of the segments indistinctly pale; the short hairs slightly 

 longer at the hind margins of the segments. Hypopygium of medium 

 size, greyish black, shining above in the middle at the base; on each 

 side there is a nearly vertical, but somewhat curved series of about 

 six strong bristles, increasing in size downwards; the posterior part 

 besides has short hairs; ventral plate black; anal tube small, blackish. 

 Legs black or blackish, front legs somewhat paler and also posterior 

 tibiæ and tarsi slightly paler; the legs are somewhat robust; the hairs 

 below hind femora short and dense at the base, longer and more 

 sparse towards the middle; bristles on hind tibiæ distinct, but small 

 and fme. Wings clear, thick veins blackish, the others more brown; 

 costa about 0,34 of the wing-length, costal divisions about as 20 — 5 — 4; 

 fork small with a small lumen; costal cilia moderately long; fourth 

 vein nearly straight, but distinctly curved dow^nwards at the end. 

 Halteres black. 



Female. Similar to the male, but the frons less broad, the palpi 

 dusky and the antennæ smaller. 



Length 1,7 — 2 mm. 



A. Mortenseni is rare; Holte ^Vs 1917, ^V? and ^7? 1918 (Th. 

 Mortensen), two males and a female. 



Geographical distribution: — Hitherto only known from Den- 

 mark. 



142. A. coacta Lundbk. 



1920. Lundbk. Vidensk. Meddel, fra Dansk naturh. Foren. 71, 26, 30. 



Male. Frons somewhat broader than high, black, slightly greyish 

 and slightly shining; bristles strong, inner bristle of lower row much 

 below the outer and a little nearer to it than to the upper supraanten- 

 nal; supraantennal bristles small and unequal, the lower quite small; 

 the upper pair close-standing, more approximate than the inner 

 bristles of middle row. Antennæ somewhat large, blackish or blackish 

 brown, arista distinctly pubescent. Palpi yellow, of ordinary size and 

 armature. Thorax black, slightly shining, with dark brownish pube- 

 scence. Pleura a little brownish, especially anteriorly. Mesopleura 

 bare. Abdomen somewhat robust, black, dull, with narrow and 

 indistinct paler hind margins to the segments; the short hairs a little 



