18 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



yellow ou the sides. -A nteunai black, third joint reddish below. Pile 

 of the face white, of the front blackish, of the vertex luteous. Dorsum 

 of thorax clothed with very short, sublntescent pile, in front obsoletoly 

 cinereous bilineate. Scutellum of the same color as the thorax, the ex- 

 treme apex testaceous. Abdomen wholly greenish black, white pubes- 

 cent. Legs yellow and ochraceous varied ; femora, on the basal half of 

 the iront and middle pairs, and the hind tarsi, except the tip, bhtck ; tip 

 of liind tibiiie and the hind metatarsi fuscous. Wings hyaline ; stigma 

 luteous. — Translated from original. 



A single female specimen from Professor Kiley agrees almost })er- 

 feetly with this, except that the dorsal stripes of the thorax'are very 

 distinct, a character, however, that is very variable in species of this 

 genus. I can see no structural differences between this and F. bicolor. 



Paragus bicolor. (Plate I, figs. 7, 9.) 



Sijr2)hiis hicolor Fabricius, Entom. Syst., iv, 297, 71, 1794. 



MitUo bicolor Fabricius, Syst. Antl., 186, 10. 



Paragus i>ico?or Latreille, Geu. Crust., xiv, 359; Meigeu, Syst. Beschr., iii, 178^ 



2 (var.); Macquart, Hist. Nat. Dipt., i, 565, 2(var.); Zetterstedt, Dipt. 



Scand., ii, 849, 1 (var.) ; Scbiner, Verb. Zool. Bot. Ges., vil, 301 ; id. Fauna 



Austr., i, 259, 

 Paragus tesiaceus Meigen, Syst. Beschr., iii, 180, 6 (var.). 

 Paragus arciiatus Meigeu, 1. c, iii, 179, 3 (var.). 

 Parar/us punctiilatus Zetterstedt, Dipt. Scaud., ii, 850, 2. 

 Paragus twniatus Meigeu, 1. c, iii, 179, 4 (var.). 

 Paragus ruficauda Zetterstedt, 1. c, 852, 5. 



Habitat. — Xorth America, Europe!. 



S 9 . Length, 4 to G""". Eyes with a distinct vertical glabrous stripe. 

 Face of male wholly' pure light sulphury yellow, the oral margin and 

 cheeks shining black; in the female there is a shining black stripe 

 reaching Irom the autenniB to the oral margin. Antenna' blackish; 

 the under side of the third joint red. Front of the female narrowed 

 above, so that at the vertex it is not more than half as wide as at the 

 base of the anteunsE; shining black, lightly dusted on the sides below; 

 frontal triangle yellow, the eyes scarcely touch each other at a point 

 midway between the ocelli and base of the antennie; vertical triangle 

 black, light pollinose in front. Thorax black, a little shining, with 

 light yellowish pile, in front with two whitish pollinose stripes. Pleur.ne 

 silvery white pilose. Scutellum with a whitish yellow border, not 

 extending to the anterior angles. Abdomen chiefly red, but variable 

 in color; first segment, black; second segment, often wholly black, 

 sometimes more or less red behind, sometimes only black on the sides. 

 The black usually extends narrowly along the sides of the third seg- 

 ment, sometimes of the fourth and fifth also; rarely the third segment 

 has a blackish band. Pile on the sides of the segments in front and on 

 the lateral margins, and on the fifth segment, white, elsewhere obscure. 

 Legs variable, frequently the basal portion of the front and middle 

 femora, and the hind femora except the tip, are black; sometimes, 



