290 DIPTERA OF NORTH AMERICA. [PART II. 



boscis whitish ; scutellum blue ; wings immaculate ; feet whitish ; 

 tergum, first segment and half of the second whitish, posterior 

 half of the second segment and third segment much tinged with 

 blue, remaining segments green. 



Length — one-fourth of an inch. 



Central nervure of the wing furcate, the exterior branch widely 

 angulated and terminating near the tip of the preceding nervure, 

 which is curved very considerably inwards, towards its tip. 



Page 85. Bolicliopus ©bscurus. 



Blackish-brassy ; wings dusky ; feet pale 



Hab. Pennsylvania. 



Head dark silvery ; antenna? black-brown ; mouth blackish ; 

 thorax and scutellum dark-brassy ; wings dusky ; feet white, a lit- 

 tle dusky on the tarsi ; poisers white ; tergum rather darker than 

 the thorax. 



Length — less than three-twentieths of an inch. 



The central nervure of the wing is nearly rectilinear, being 

 hardly perceptibly reflected. 



Page 86. Dolicliopus femoratus. 



Green ; tibiae and tarsi whitish. 



Hab. Pennsylvania. 



Body brilliant green, with bluish reflections ; front- pruinose ; 

 antennae blackish ; proboscis yellowish ; wings hyaline ; scutellum 

 blue ; thighs green and excepting the posterior ones, whitish at 

 tip, tibiae white, tarsi dusky ; tergum, ultimate joints cupreous at 

 their bases. 



Length — three-twentieths of an inch. 



The brilliancy and shade of green in this insect are similar to 

 D. sipho ; when living, and in the sun's rays, it resembles bur- 

 nished gold, nervures nearly as in sipho. 



Say, Journ. Acad. Nat. Sc. Philad, Vol. VI. 

 Page 168. Psilopus fenioratws. 



This brilliant species varies in the color of its thighs, which in 

 my description are stated to be green ; a specimen taken in Indiana 

 has whitish thighs. 



