OF WASHINGTON. 97 



Apical cell closed in the border at the apex of the wing ; wings longer 

 than the abdomen, not widened and triangular ; flexure of the 

 fourth longitudinal vein rounded ; hind cross- vein somewhat 

 curved; antennae half as long as the face, third joint nearly 

 twice as long as the second gen. Acaulona 



Apical cell closed and petiolate 4 



4. Fourth longitudinal vein bent at an angle to meet the third ; petiole 



of the apical cell very long ; hind cross-vein near the middle of 

 the apical cell ; face with a median carina....gen. Himantostoma 



Fourth longitudinal vein nowhere bent at an angle, but describing a 

 curve to meet the third ; wings very wide (gen. Alophora sens. 

 Schin.) 5 



5. Hind cross- vein nearer to the bow of the fourth longitudinal than to 



the small cross-vein ; petiole of the apical cell moderately long, 



first longitudinal vein elongate g en - Alophora s. sir. 



Hind cross-vein situated at or before the middle of the distance be 

 tween the bow of the fourth longitudinal and the small cross- 

 vein ; petiole of the apical cell long, first longitudinal vein not 

 elongate subgen. Hyalomyia 



Acaulona v. d. Wulp, Biol. Centr.-Am., Dipt., II, 4. (1888.) Mexico 

 (Orizaba ; Vera Cruz). Larval habits unknown. 



Alophora Rob. Desvoidy, Myod., 293-4. (1830.) Nevada, Rocky Mts. 

 [Bigot, Ann. Soc. Ent. Fr., 1888, 255.] The habits of the European A. 

 dispar were discovered by L. Dufour. The larva lives parasitically in the 

 body of Brachyderes lusitanicus (Schiner). The species referred to this 

 genus by Bigot perhaps belong to Hyalomyia. We have no other au 

 thority for its occurrence in North America. 



Himantostoma H. Lcew, Centur. IV, No. 87. (1863.) tf. Illinois. 

 Larval habits not known. 



Hyalomyia Rob. Desvoidy, Myod., 298. (1830.) New York ; District 

 of Columbia ; Dakota ; Pacific Coast. Larval habits probably same as 

 Alophora. 



Phasia Latreille, Hist. Nat. Crust, et des Ins., XIV, 379. (1804.) The 

 larval habits of a European species are known. L. Dufour found the 

 pupa in the body of a Pentatoma grisea. The, larvae are parasitic on the 

 adults of other insects (Schiner). This genus has been wrongly identified 

 as occurring in North America. 



Trichopoda Latreille, Cuv. Regne An., V. (1829.) United States ; Mex 

 ico ; Guatemala ; West Indies. This genus, rich in species, is peculiar to 

 the American continents. Its habits have never been recorded. 



Xysta Meigen, Syst. Beschr., IV, 181. (1824.) Illinois. Larval habits 

 unknown. 



