326 PROCEEDINGS OF THE NATIONAL MUSEUM. 



ERISTALIS VIRIDIS, new species. 



Male and female: Head polished ^reen, tlic sides of the front, the 

 entire f;i(;e except the tuberele, also the oeciimt and cheeks next the 

 eyes, opaque, wliitish i)ruinose; hairs of the head yellow or whitish, 

 those of the vertex chiefly black; antennae yellow, the arista bare; 

 eyes bare, not distinctly spotted. Thorax i)olished green, marked with 

 four velvet-])hick vittae, the outer ones interruj^ted at the suture; i)Os- 

 terior margin of thorax also velvet black, pleura thinly gray pruinose; 

 hairs of thorax short and rather s])arse, yellow; scutellum polished 

 green, its base opaque, velvet-black, the hairs yellow. Abdomen pol- 

 ished green, second segment marked with an H-shaped velvet-black 

 spot placed transversely; the tiiird with a velvet-black fascia behind 

 the middle, emarginate in the middle of its ])osterior side and prolonged 

 anteriorly in the middle to the front end of this segment; fourth seg- 

 ment with a velvet-black dot in front of its center; hairs of abdomen 

 rather sparse and short, yellow. Legs black, apices of femora and 

 broad l)ases of tibiae, yellow, first Joint of front and middle tarsi reddisii 

 brown. Wings hyaline, stigma gray, a small spot at its base, yellow. 

 Halteres yellow. Length, S) to 12 mm. A specimen of each sex (No. 671). 



Type.—^i). :399(), U.S.N.M. 



HELOPHILUS VIRGATUS, new species. 



Male and female: Head polished black, the vertex opacjue, browu 

 X>ruinose, the occiput, sides of the fa(;e and in the male the entire front 

 except a triangular spot above the antennae, in the female only its 

 sides, opaque, yellowish-gray pruinose; hairs of. the head yellow, in the 

 male those of the vertex, in the female those of the entire front, black; 

 antennae brown, 4)artly or largely yellow, the arista yellow, bare; ey(!S 

 bare. Thorax opacpie, velvet black, two vittae and the lateral margins 

 yellow pruinose, pleura thinly gray ])ruinose, hairs of thorax short but 

 rather dense, yellow; scutellum polished yellow, its hairs also yellow. 

 Abdomen black, the sides of the first segment and a spot on each side 

 of the second, usually yellow; the first .segment ancia fascia in front of 

 the middle of the others, gray pruinose, that on the fifth segment in the 

 female interrupted in the middle, boidered in front and behind with 

 velvet-black, the jmstcrior and lateral margins of each of these seg- 

 ments polished bluish-black; hairs short, sparse, black and yellow. 

 Legs black, apices of tiie front and middle femora, basal two thirds of 

 the front tibiae, the entire middle tibiae and the first two joints of their 

 tarsi, yellow; posterior femora greatly thickened, their tibiae strongly 

 arcuate. Wings hyaline, the stigma brown. Halteres yellow. Length, 

 14 to 17 mm. Four males and live females (No. <>(>.'>). 



Tt/pe.—m). 39!)7. U.S.N.M. 



