OF PHILADELPHIA. 361 



the segments : venter wliitish, at tip black : feet black ; tlbite at 

 base white ; tarsi at base tinged with rufous. 



Length seven-twentieths of an inch, the other sex half an inch. 



If it be true that the male in this genus, is distinguished [168] 

 invariably by the contact of the eyes on the vertex, then the 

 male of the present species is nearly double the size of the fe- 

 male, and the former has the more densely plumose antennae ; in 

 this case also the female of the violacea has the loosely plumose 

 antenna), and the female of i\\Q postica has the loosely plumose 

 antenna). 



PSILOPUS Meig. 



1. P. FEMORATUS. — Dolichopus /enwratus nob. Jour. Acad. 

 Nat. Sci., vol. iii. p. 8G. [Ante, 76.] 



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. 



2. T. PATiBULATUS nob. — Dolichopus patihidatm Journ. Acad. 

 Nat. Sci., vol. iii. p. 87. [Ante, 7G.] 



This species also occurs in Mexico. 



CHRYSOTUS Meig. 



1. C. NUBILUS. — Blackish ; feet dull honey-yellow. 

 Inhabits Indiana. 



Body blackish : head dull plumbeous : thorax cinereous, with 

 three brown lines : wings immaculate : poLsers white : feet dark 

 honey-yellow ; thighs black at base and above. 



Length rather over one-tenth of an inch. 



2. C. CONCINNARIUS. — Green-brassy ; tergum blue towards the 

 tip. [169] 



Inhabits Mexico. 



Head violaceous, with a. cinereous reflection: palpi with a ci- 

 nereous reflection : antennaD black : thorax green with a gray oli- 

 vaceous reflection : wings hyaline, obsoletely tinged with yellow- 

 ish on the costal margin : poisers white : tergum with a gray re- 

 flection, brassy-green at base, and violaceous towards the tip : 

 thighs green ; tibias whitish. 



Length one-fourth of an inch. 

 1829.] 



