103 



those of middle ones as 30-17-12-8-8; hind tarsi with their joints as 24-25- 

 18-12-8. Calypters and halteres yellow, the former with black cilia. 



Wings grayish, darker in front ; third and fourth veins about parallel beyond 

 the cross-vein ; last section of fifth vein about 33, of cross-vein about 1 1 fiftieths 

 of a milUmeter. 



Described from two males taken at Kingston, Rhode Island, 

 July, by John Barlow. Holotype in the collection of the Boston 

 Society of Natural History. 



Gymnopternus nigricoxa, new species. 



cf. — Length 4 mm.; of wing 4.5 mm. Face wide for a male, white. 

 Front thickly covered with white pollen, still the bluish-black ground-color 

 can be seen through it when viewed in certain directions. Antennae wholly 

 black; third joint about as long as wide, somewhat rounded at tip; arista nearly 

 basal. Orbital cilia wholly black. Palpi and proboscis black. 



Dorsum of thorax blue-black, sometimes almost violet, with brown pollen 

 which does not dull it, except when viewed obliquely; pleurae more black with 

 gray pollen. Abdomen dark green with whitish pollen on its sides. Hypopy- 

 gium and its lamellae wholly black, the latter rather narrow, crescent-shaped, 

 fringed with little black hairs; central filament yellowish. 



All coxae and femora black, extreme tips of coxae, trochanters, and extreme 

 base and broader tips of femora yellow. Anterior surface of fore and middle 

 coxae covered with black hairs. All tibiae yellow, posterior pair black at tip 

 for nearly one-fourth their length. Fore tibiae with the usual row of little 

 bristles rather large and reaching nearly their whole length; there are several 

 much longer bristles in the row. Middle tibiae with one large bristle near the 

 middle of lower surface on anterior edge, and five large bristles above. Hind 

 tibiae with five or six bristles above and one large one near apical fourth below. 

 Fore and middle tarsi a little longer than their tibiae, black from the tip of the 

 first joint; hind tarsi wholly deep black. Joints of fore tarsi as 35-16-12-9-7; 

 of middle tarsi as 49-28-23-15-11; those of hind tarsi as 35-42-29-17-12. 

 Calypters and halteres pale yellow, the former with black cilia. 



Wings tinged with brown, which is slightly darker in front of third vein, 

 the cross-vein narrowly clouded; third and fourth veins nearly parallel beyond 

 the cross- vein, still the third is a little bent backward at tip; last section of 

 fifth vein about one and a half times as long as the cross-vein. 



9 . — The female agrees with the male in all color characters, in size and in 

 the wing characters. 



Described from one male (holotype) taken at Watchogue, Long 

 Island, New York; one female (allotype) taken at Protection, 

 Erie Co., New York, June 16; one male taken at Wells, New York, 

 July 16, by D. B. Young; two males and two females taken in 

 Massachusetts, one at Winchendon, July 5, one at Wellesley, 

 July 18, one at Medford, June 23, and one at Saxonville, by 

 A. P. Morse; one male taken at Joliette, Quebec, July 15. 



Type in the author's collection. 



Gymnopternus obtusicauda, new species. 



cf. — Length 3.5 mm.; of wing the same. Face rather wide, grayish 

 white. Front blackish, covered with white pollen which scarcely conceals 

 the ground-color. Palpi and proboscis black. Antennae black; third joint 

 as long as wide, rounded below, the tip being a little pointed at upper angle; 

 arista inserted near the base. Orbital cilia wholly black. 



Thorax and abdomen dark greenish; pleurae with gray pollen; hairs of the 

 abdomen black, still sometimes they have a reddish appearance when viewed 



