or PHILADELPHIA. 865 



OCYPTERA Fabr. 



0. ARCUATA. — Wings blackish on the costal margin ; apical 

 cross-nervure arquated at its origin. [174] 



Inhabits Indiana. 



Body blackish : hypostoma yellowish-white ; orbits, excepting 

 behind and on the vertex, honey-yellow with a gray reflection : 

 front with a dilated blackish vitta : antenna) with the base of the 

 third joint obsoletely honey-yellow beneath : thorax with yellow 

 hair before the wings : wings hyaline : costal margin blackish ; 

 terminal cross-nervure not angulatcd at its origin : halteres yel- 

 lowish : wing-scales white : feet black ; base of the thighs and 

 coxae yellowish: tergum pale j'cllowish; basal segment with the 

 ba.se and dorsal line black ; second segment with a large black 

 triangle; third segment with a gray reflection each side; re- 

 maining part black : venter pale yellowish, at tip black. 



Length three-tenths of an inch. 



This may readily be distinguished from other species, by the 

 form of the apical cross-nervure. 



MILTOGRAMMA Meig. 



M. TRiFASCiATA. — Tcrgum black, fasciate with gray. 



Inhabits Indiana. 



Hypostoma and posterior and inferior orbits honey-yellow, with 

 a silvery reflection : antennas honey-yellow ; seta with dense 

 short hairs : frontal vitta of equal breadth : thorax gray, with 

 many obsolete abbreviated blackish lines : scutel gray : tergum 

 black ; segments, except the basal, silvery-gray [175] on the 

 basal half: venter the same: feet black; thighs on the exterior 

 .side with a gray reflection ; wings tinged with brownish. 



Length less than half an inch. 



CfONIA Meig. 



G. FRONTOSA. — Front very prominent, abdominal segments 

 whitish at base. 



Inhabits Upper Missouri. 



Body black, with rigid hairs : head pale yellowish-white, seri- 

 ceous : front very prominent, gibbous : eyes placed very far back, 

 oblong-oval, chestnut-brown : etemmata black : antennao black- 

 1829.] 



