136 BULLETIN 116, UNITED STATES NATIONAL MUSEUM. 



cilia of calypters sometimes black, although they seem to he yellow 

 in most specimens. The fifth joint of fore tarsi more or less yellow, 

 usually colored as in the male. 



Redescribed from the type material and specimens from the fol- 

 lowing locations: Bennington, Vermont, June 24; Eastport, Maine, 

 Juh^ 14; Southwest Harbor, Maine, July 10; Cohasset, Massachusetts, 

 June 10; Big Stone City, South Dakota; Toronto, Ontario, May 23; 

 Montreal, Quebec, June 7; Hood River, Oregon, June 3 and 4, 1917. 

 (Cole). 



Ty^pe locality. — Illinois. 



Tyjye. — In Museum of Comparative Zoology, Cambridge, Massa- 

 chusetts. 



No. 90. DOLICHOPUS SOCIUS Loew, var. GLADIUS, new variety. 



Male. — Length 3.5-4.5 mm. ; of wing the same. Face of moderate 

 width, narrowed below, silvery white. Front shining green. Anten- 

 nae black; first joint yellow below; third joint oval, usually with an 

 obtuse point at tip, but sometimes rounded. Lateral and inferior 

 orbital cilia yellowish white, a few of the upper cilia black. 



Thorax shining green with more or less coppery reflections on the 

 dorsum, which often form two distinct narrow vittae, leaving a 

 green stripe between them; pleurae dulled with gray pollen. Abdo- 

 men green with coppery reflections and narrow black incisures, and 

 with spots of white pollen on the sides of the segments. Hypopygium 

 black, its lamellae of moderate size, somewhat oval in outline, nearly 

 one and a half times as long as wide, w^hite with narrow black border, 

 jagged and bristly on apical margin, otherwise fringed wdth delicate 

 black hairs. 



Fore coxae wholly or almost w^holly yellow, anterior surface wdth 

 silvery pollen and minute pale hairs; middle and hind coxae black 

 with yellow tips. Femora and tibiae yellow. Middle and hind 

 femora each w^ith one preapical bristle, the latter with a row of 

 delicate little yellow hairs on low^er inner edge and with the black 

 hairs on upper edge becoming longer at base, posterior tibiae w^ith their 

 tips black for about one-sixth their length. Fore tarsi slightly 

 longer than their tibiae, black from the tip of the first joint, which is 

 about as long as the two following taken together, second a little 

 longer than third, fourth and fifth of about equal length, each 

 shorter than the third. Middle tarsi about one and a fourth times 

 as long as their tibiae, black from the tip of the first joint. Hind 

 tarsi wholly black. Calypters, their cilia, and the halteres yellow. 



Wings (fig. 90) grayish, often distinctly tinged with brown in front 

 of the third vein; costa with a very slight knotlike enlargement at 

 tip of first vein; last section of fourth vein a little bent before its 

 middle; hind margin of wing scarcely indented at tip of fifth vein; 



