ORTALID^E — MELANOLOMA. 193 



Arista thin and apparently bare. Thorax strongly built; the 

 fallow-yellowish pubescence of its dorsum very short ; the ordi- 

 nary bristles black. Scutellum convex, with four bristles. The 

 perpendicular mesonotum, the pleurae and the pectus of the same 

 color as the upper side of the thorax. The mesothoracic bristle 

 strong, black, and hence very conspicuous ; the prothoracic 

 bristle thin and fallow-yellowish, and hence easily overlooked. 

 The metallic-blue abdomen is of a rounded-oval shape and is 

 covered with shallow scars, which diminish its lustre ; its short 

 pubescence is whitish on the first segment only, otherwise rather 

 blackish. Feet of a yellowish-ferruginous color, only the dis- 

 tinctly arcuate hind tibiae are gradually infuscated towards the 

 basis ; the tarsi, beyond the second joint, are more or less ferru- 

 ginous-brownish. Femora not incrassate, only the hindmost 

 ones with spines near the tip. Wings hyaline ; the costal cell, 

 the stigma, and a narrow border, running from it to the fourth 

 longitudinal vein, along the margin of the wing, black ; the small 

 crossvein likewise with a narrow black cloud ; a blackish spot 

 lies between the extreme basis of the submarginal cell and the 

 end of the costal cell. The second longitudinal vein reaches the 

 anterior margin rather far from the apex of the wing ; the third 

 longitudinal vein is very straight ; the small crossvein is a little 

 beyond the middle of the discal cell, which is considerably narrower 

 before this crossvein than after it; posterior crossvein straight, a 

 little oblique ; the last section of the fourth longitudinal vein 

 rather long, parallel to the third vein ; posterior angle of the 

 anal cell quite obtuse. The microscopic pubescence of the 

 surface of the wing is comparatively sparse and coarse. 



Hab. Brazil. 



Observation. — M. cyanogaster Wied. is not quite as large as 

 the above-described species ; its wings are comparatively smaller 

 and the black border along the costa is somewhat broader at the 

 apex of the wing ; the lateral bristle of the front is somewhat 

 more removed from the bristles on the vertex ; the shallow pits 

 on the front are not perceptible ; the pubescence of the thoracic 

 dorsum is considerably longer; the pleurae and the tibiae are 

 blackish-brown. 



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