SOUTH AMERICAN DIPTERA. 271 



VOLlCEL,L,A. 



TABLE OF SPECIES. 



1. Scutellimi with six stout spiniferous tubercles soiitellata. 



Scutellum without tubercles ; with or without bristles 2. 



2. Deep metallic species, the abdomeu without light markings 3. 



More or less reddish, yellowish, or brownish, the abdomen not uniformly 



dark metallic 6. 



3. Face and front metallic like the thorax 4. 



Face and front reddish yellow; wings with a large quadrate brown spot. 



iiiereti'ioias n. sp. 



4. Second longitudinal vein sinuous before its tip, marginal cell petiolate; third 



joint of antenuse short 5. 



Second vein regular, ending in the costa or tip of first vein...viri€lis u. sp. 



5. Briglit metallic, usually green, species; wings nearly hyaline at base. 



obesa. 

 Deep blue : wings deep brown at base seniiila n. sp. 



6. A transverse row of bristles on the mesonotum in front of the scutellum...?. 

 No such bristles present 9. 



7. General color metallic reddish ; a well defined quadrate spot on the wings. 



uiaciila. 



Mesonotum deep blue, with violet reflections; wings clouded distally ; more 



elongate species 8. 



8. Front black ; marginal cell petiolate presciitellaris n. sp. 



Front reddish yellow ; marginal cell closed in the costa, or ojien. 



persi mills n. sp. 



9. Second longitudinal vein strongly sinuous near the tip ; wings variegated. 



picta. 

 Second vein regular, not bent into submarginal cell. 10. 



10. Face acuminate, projecting strongly forward; front shining black; dark 



species ; wings without dark spot fu$iicipeiiiii!«. 



Face not remarkably acuminate, not projecting strongly forward ; largely 

 reddish or yellowish species 11. 



11. Disk of mesonotum black or metallic brown ; marginal cell open or briefly 



petiolate 12. 



Mesonotum reddish or yellowish 13. 



12. Legs black, femora, except distal fourth, light yellow ; mesonotum shining 



black, with the lateral margins yellow innsta n. sp. 



Legs reddish brown ; mesonotum metallic brown, the sides and posterior 

 expansion yellow inus n. sp. 



13. Wings pure hyaline, stigma minute pallens. 



Wings clouded distally ; stigma small ? puuctifiera. 



44. Yolucella ««cutellata Macq. 



Two female specimens I doubtfully refer to this species. They 

 have the six singular spiniferous tubercles on the scutellum. The 

 face is in no wise black below, the red pile of the front is only black- 

 ish in certain reflection, the pile of the mesonotum is wholly light 

 fulvous and not at all black, and the wings are hyaline with a quad- 



