A Monograph o/ Kfiyiilinn Dijilem. 59 



7. ACIURA, Robineau-IJesvoiuy 



Rob.-Desv., Myod., 773. 12 (1830). 

 Platyparea p.p., l,w., Trypetid., 26. (1S62). 



AUied to Si)heniscomyi(i but distiiiguished from it as well us 

 from other gênera by the présence always of only one ])air of h. se, 

 the 3 i.ov., and usually by the pattern of the wings which are black 

 with hyaline indentations and hyaline spots. 



Head broader than high; frons very slightly narrowed for- 

 ward ; face a little concave ; eyes large and rounded ; cheeks narrow ; 

 epistoma not prominent; proboscis short: palpi small and bristly; 

 antennae inserted towards the middle of the eyes, with the third 

 joint rounded, fairly pointed at the end and delicately pubescent; 

 arista short, pubescent or almost bare; oc. présent, weak or strong; 

 s.ov.'i, i.or.S, or s.or.l, i.or.S; pot. parallel ; ocj). weak to well deve- 

 loped. The chaetotaxy of the head is composed of bristles which vary 

 from black and thin in the typical species to ail yellow and thin in 

 some American species, while in one Indian species {xn/ithotrica, 

 Bezzi) those on the v^rtex are yellow^ short and stout and the others 

 black; ail thèse above mentioned characters .show decidedly, in mv 

 opinion, that the genus is still composed of heterogeneous éléments. 



Thorax very convex., rounded and with a complète chaetotaxy; 

 pt. strong; 1 strong mpl. ; scutellum small, convex and bearing only 

 two strong b.sc. 



Abdomen convex, narrowed at the base and with or without 

 small apical and latéral bristles. Ovipositor very variable, either 

 short, broad and flattened, or long narrow and less flattened, or it 

 may be longer than the abdomen. 



Legs normal in shape and size with the front femora bristly 

 below and the middle tibiae bearing a single .spur. 



Wings elongated. black with both hvaline indentations and dis- 

 cal spots, and with the pattern variable ; there are usually two hya- 

 line triangular indentations in the middle of the costa after the 

 stigma. while in Spheniscomyia only one such indentation is pre- 

 .sent. RI very short, ending well before the middle of the wing; 

 R2 + 3, R4 + 5 and Ml rather curved ; R4 + 5 bare; radio-median and 

 médian cross veins approximate, the former being placed in the 



