ARGYRA. 127 



cans or some similar American species, and that Meigen was mis- 

 taken when lie believed it to be identical with the common European 

 species. Such a supposition, however, would be erroneous. 

 Fabricius in his older works (of which at present I cannot com- 

 pare only the Mantissa II), mentions everywhere Europe as the 

 habitat. The statement of the Systema Antliatorum is, there- 

 fore, either a mere mistake, or Fabricius confounded later an 

 American species with the European one. Even in the latter case 

 the name cannot be transferred upon the American species. The 

 first, however, seems to be more probable, because Fabricius 

 in the Systema Antliatorum, quotes his former works without 

 the least hesitation, and declares that America is the habitat of 

 this species, without mentioning at all that he is thus in contra- 

 diction with his own previous statement. 



II. SCUTELLUM WITHOUT HAIRS. 

 A. Abdomen somewhat conical, glittering with white. 



2. A. nigripes, n. sp. % .—Ex viridi laete chalybea, abdomine albo- 

 micante, fronte et facie atris, velutinis, pedibus nigris, tibiis anticis 

 totis, reliquis ex parte flavicantibus. 



Green-blue, with the abdomen glittering white; front and face velvet- 

 black ; feet black, the fore tibiae entirely and the four posterior tibife 

 partially yellowish. Long. corp. 0.17 — 0.18. Long. al. 0.17. 



Green-blue. Front and face velvet-black, without pale dust. 

 Palpi and proboscis black. .The first joint of the antenna? with 

 a comparatively long and close pubescence. Upper side of the 

 thorax and of the scutellum shining; the latter, as far as percepti- 

 ble, without hair. Abdomen without transparent yellow spots 

 upon the anterior segments, and with a thick glittering-white dust, 

 which becomes thinner only towards the basis of the abdomen. 

 The small lamella? of the hypopygium are brownish-black. Coxae 

 black; fore coxa? with coarse black hairs. Femora brownish- 

 black, the extreme tip of the four anterior ones yellow ; they have 

 only short hairs and short bristles. Fore tibia? yellow, on the 

 upper side with less numerous, bul stronger hair-like bristles, on 

 the hind side with more numerous but more slender hair-like bris- 

 tles of considerable length. Middle tibiae upon the whole upper 

 side yellowish, upon the under side blackish-brown : they have 

 upon the under side, upon the middle of the anterior side and 



