202 BULLETIN 116, UNITED STATES NATIONAL MUSEUM. 



lamellae of medium size, ovate, white, with a rather narrow black border, on the 

 apical margin jagged and fringed with black bristles. Four posterior coxae blackish 

 with yellow tip. Fore coxae yellow, only somewhat blackened at the extreme basis, 

 beset upon the anterior side with delicate black hairs, which reach nearly to their 

 base. Feet pale yellow. Hind femora before the tip with a bristle, upon the under 

 side only with very short minute pale hairs. Hind tibiae stout but not exactly 

 thickened, upon the first half of the hind side without hairs, at the extreme tip brown- 

 ish. Fore tarsi twice as long as the tibiae; their first four joints very thin, yellow; first 

 joint as long as the three following ones together; tnird somewhat shorter than the 

 second; the fourth hardly half as long as the third; the fifth joint black, flattened, 

 broad, still not as large as in D. hatillifer; upon its upper margin it is beset with 

 appressed minute black hairs. Middle tarsi from the tip of the first joint blackened ; 

 hind tarsi entirely black. Cilia of the tegulae yellowish-white. Wings hyaline; near 

 the tip of the first longitudinal vein with a long but not very thick swelling, which 

 gradually merges into the costa; fourth longitudinal vein not broken. 



Female. — Wings and feet plain, fore tarsi from the tip of the first joint blackened. 

 All the rest as in the male. 



The single type specimen which I found at the Museum of Com- 

 parative Zoology in January, 1919, had been entirely destroyed, ex- 

 cept the wings, which still adhere to the pin; from which I made 

 the following notes: 



The costa is distinctly enlarged, the enlargement beginning a little 

 before the tip of the first vein and gradually tapering to the tip of 

 the costa, this enlargement although distinct is rather small; the 

 bend in the last section of the fourth vein is just beyond its basal 

 third and beyond this bend the fourth vein is distinctly arcuated; 

 the third vein is also considerably and rather evenly arcuated from a 

 point nearly opposite the cross-vein to its tip (this is a rather peculiar 

 character); the second vein also shows a little of this arcuation; the 

 hind margin of the wing is quite evenly rounded, the anal angle being 

 rounded, not at all prominent; the hind margin at the tip of the fifth 

 vein is a little drawn in from both sides so as to form a slight sinus, 

 but there is scarcely an indentation at tip of fifth vein in the usual 

 sense used in these descriptions. 



Type locality. — Fort Resolution, Hudson Bay Territory. 



No. 144. DOLICHOPUS DISCIFER Stannius. 



Dolichopus discifer Stannius, Isis, 1831, p. 37.— Schiner, Fauna Austr., vol. 1, 

 p. 216.— LoEW, Mon. N. Amer. Dipt., pt. 2, 1864, p. 71.— Coquillett, Proc. 

 Wash. Acad. Sci., vol. 2, 1900, p. 423.— Lundbeck, Dipt. Danica, vol.4 

 1918, p. 95. 



Dolichopus tanypus Loew, Neue Beitr., vol. 8, 1861, p. 71. 



Hale. — ^Length, 4.75-5.5 mm.; of wing, 5-5.5 mm. Face of mod- 

 erate width, rather long, silvery wliite, sometimes a little yellowish 

 on the upper part. Front shining green. Antennae black; first joint 

 yellow below on lower half or more; third joint large, about two and 

 a half times as long as wide, somewhat elliptical in outline, rather 

 pointed at tip; arista inserted beyond the middle of the third joint. 



