105 



32-16-12-8-9; of middle ones as 44-25-19-14-12; those of hind tarsi as 31- 

 38-26-17-13. Calypters and halteres pale yellow, the former with black 

 cilia. 



Wings dark grayish, scarcely darker in front; costa rather thick, especially 

 from the tip of the first vein, which is about half as far from the root of the wing 

 as the cross- vein; third vein distinctly bent backward at tip so as to approach 

 fourth a little; fourth ending slightly before the apex of the wing; last section 

 of fourth vein 45, of cross-vein 24 fiftieths of a millimeter. 



Described from eight males from Erie Co., New York: five 

 were taken at Lancaster, June 4; two at Colden, May 31; and one 

 at Springville, June 7; also one male taken at Machias, Maine, 

 July 22, by C. W. Johnson. 



Holotype taken at Lancaster, New York, and in the author's 

 collection. 



This differs from Gymnopternus chalcochrus Loew in having the 

 face white and the third vein bent a little backward at tip, while 

 in that species the face is distinctly yellow and the third vein is 

 almost exactly parallel with fourth from the cross-vein to its tip. 



Pelastoneurus cristatus, new species. 



c? . — Length 3 mm.; of wing 2.4 mm. Face moderately wide, silvery 

 white, still the green ground-color showing through on upper part. Palpi 

 covered with white pollen. Front blue or violet, rather dull. Antennae 

 yellow; third joint about as long as wide, rounded at tip, brownish; arista 

 brown, feathered with rather long hairs on apical half. Orbital cilia wholly 

 black. 



Thorax with anterior half of dorsum dark green, dulled with brown pollen; 

 posterior half of dorsum and the scutellum deep violet, shining; pleurae green 

 with white pollen; there is scarcely a trace of the usual black stripe above the 

 root of the wing. Abdomen green with conspicuous spots of white pollen on 

 the sides of the segments; its hairs black. Hypopygium black; its basal 

 portion small, about the size of the small lamellae, which are blackish, some- 

 what obcordate with the upper lobe the largest; they are covered with long 

 hairs; there are two pair of inner appendages, one short, horn-like, pointed at 

 tip, and bare; the other pair are long and slender with several branched bristles 

 near the tip. 



Fore coxae yellow, blackened a little at base, this infuscation extending 

 nearly to the middle on outer surface, their anterior surface with a few minute 

 black hairs, and a row of black bristles on apical half; prothorax with a large 

 black bristle above the fore coxae. All femora and tibiae yellow, hind femora 

 narrowly black at tip; hind tibiae sometimes slightly brownish at extreme base 

 and tip. Fore tarsi yellow with last two joints brown, they have long tomen- 

 tum on the lower surface; this is snow white and nearly as long as the thickness 

 of the joints, giving the tarsi something of a compressed appearance. Middle 

 and hind tarsi black from the tip of the first joint, still the posterior pair are 

 blackish almost to their base. Joints of fore tarsi as 19-10-7-5-7; of middle 

 ones as 30-45-13-9-9; and of hind ones as 21-32-24-16-12. Calypters and 

 halteres yellow, cilia of the former black. 



Wings tinged with brown; third vein bent backward at tip; last section of 

 fourth vein bent near its middle, ending close to the tip of third vein; last 

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



Described from two males. The holotype was taken at 

 Eastham, Massachusetts, June 27, by C. W. Johnson; the 

 paratype was taken at Hampton, New Hampshire, August 8, 

 1923, by S. Albert Shaw. 



