DIPTERA. 489 



My Sphecomyia undata has the slender form of a Sphex or 

 mud-wasp. It is of a light brown color, darker on the back, 

 and on the middle of the thighs and shanks; its head is coni- 

 cal, and bears the antennie on the tip of the cone; its wings 

 are brown on the outer part, with a small transparent spot 

 near the edge, and the inner part is transparent in two large 

 wavy spaces. It is about five eighths of an inch long, and its 

 wings expand one inch and a quarter, or more. It is possible 

 that this singular fly may be the Pyrgota undata of Wiede- 

 mann. An insect, closely resembling it, is figured in Griffith's 

 translation of Cuvier's " Animal Kingdom," under the name 

 of Myopa nigripeiinis. It is found on fences around gardens 

 in May and June. It sits with its wings half spread, moves 

 slowly, and flies heavily. My Sphecomyia valida, though rather 

 shorter than the preceding, has a thicker body. Its color is 

 brownish yellow, and it is striped with brown. The wings 

 are transparent, and are mottled with small, dusky spots. 



Some of the Conopians (Coiiopidce) still more closely re- 

 semble slender-bodied wasps than the preceding Sphex-flies. 

 Coiiops sag-ittaria, of Say, (nigriconiis, Wiedemann) might 

 almost be mistaken for a species of Eumenes. Its hind body 

 is very slender and cylindrical next to the thorax, and swells 

 out behind. Its antennas are long, and thickened towards the 

 end. Its proboscis is very long and slender, elbowed at the 

 base, and extends far beyond the head. This fly is of a black 

 color; the rings of the hind body are edged with white; the 

 face is yellow; the legs are brownish yellow, shaded with 

 black on the thighs; and the wings are black, with two un- 

 colored and wavy spaces on the inner margin. Its body is 

 five eighths of an inch long, and its wings expand rather more 

 than three quarters of an inch. This fly may be found suck- 

 ing the honey of flowers in June and July. The Greeks gave 

 the name of Conops to some stinging fly or gnat. The Cono- 

 pians undergo their transformations in the bodies of humble- 

 bees, their young subsisting on the fat contained within the 

 abdomen of their luckless victims. 



A host of flies, forming nearly one third of the whole num- 

 ber of species in the order Diptera, will be found to have a 

 62 



