46 Orthorrhapha hracliyceia. 



and more conspicuous at tlie apex: venter with long, yellowish grey 

 hairs. Feniora black with yellow tips; til)iæ yellovv with a more 

 or less distinet, small. Ijlaclc ring in the middle: tarsi yellow. Wings 

 yellowish with yellow veins. Halteres bright yellow with a darker 

 l)edimcle. 



Female. Face yellow with a broad, black middle line, vertex 

 black ; hinder eye-margin yellow, broad. Thorax a little shorter haired 

 than in the male and with a more or less distinet, yellow spot on the 

 pleura in front of the wing-root. Femora reddish yellow wilii blackish 

 rings before the tips, the black colom' especially extended on the 

 under side. 



Length 14 — 15,5 mm. 



This species is distinguished from -S. furcata by the eyes being 

 l)are and unicolorous in both sexes. and the venter being chiefly 

 yellow ; in tlie male it difters by the rather broad hind margin on the 

 side of the eyes and the yellow stripe at the inner eye-margin. and 

 in the female by the yellow face, the black vertex without yellow spots, 

 and the yellow eye-margin. 



S. chamæleon is not rare, though not so common as furcata ; 

 vicinity of Copenhagen. Ordrnp Mose, Hillerød, Donse Dam. Jægerspris 

 and at Svenstrup; Funen at Odense. My dates are '■' >; — -'• :. 



Geographical distribution : — Northern and Middle Europe, from 

 middle Sweden down in France. 



4. S. potamida Meig. 



1822. Meig. Syst. Beschr. III. 136, 3. — 1849. Zett. Dipt. Scand. VIII. 

 2952, 1—2.- 1862. Schin. F. A. I, 15. — 1903. Kat.palaarkt.Dipt.il, 21. 



Male. Eyes bare, the facets in the lower part considerably smaller 

 than above, the dividing line sharp, the small facets stretching a littie 

 upwards at the hind margin. Eyes. as far as I have seen, unicolorous. 

 Face black, the cheeks with yellow side spots; below the antennæ 

 black or brown haired, farther downwards yellow haired. Antennæ 

 black. Thorax black. densely. but somewhat short, yellow haired. 

 Scutellum yellow with a semicircular, black, basal spot. Abdomen 

 black, dull on account of the very short, dense pubescence; a sub- 

 triangular, bright yellow spot on each side nn the second segment, 

 and narrow transverse side stripes at the hind margin nn the third, 

 sometimes connected in the middle, thus forming a transverse band, 

 on the fourth segment a yellow hind margin, being broadest at the 

 sides, flfth segment with a yellow spot at the hind margin, somewhat 

 produced in front. Abdomen spaiingly clothed with long, chiefly dark 

 pubescence. From the produced apical spot a faint trace of a reddish 



