42 DIPTERA OF NORTH AMERICA. [PART II 



joint rather blunt at the tip. Face ochre-yellow ; palpi yellow. 

 Cilia of the inferior orbit pale yellowish. Hypopygium black ; 

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

 border, on the apical margin jagged and fringed with black bristles. 

 Tour posterior coxae blackish with yellow tip. Fore coxae yellow, 

 only somewhat blackened at the extreme basis, beset upon the an- 

 terior side with delicate black hairs, which reach nearly to their 

 base. Feet pale yellow. Hind femora before the tip with a bris- 

 tle, 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 brownish. Fore 

 tarsi twice as long as the tibiae ; their four first joints very thin, 

 yellow ; first joint nearly as long as the three following ones 

 together ; the third 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. batillifer ; 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. 



Sab. Fort Resolution, Hudson's Bay Territory. (Kennicott.) 

 Observation. — The resemblance of the present species with D. 

 subciliatus is so great that, as both occur in the same region, I 

 was for a long time in doubt whether I should consider" them as 

 two species. As the unfringed under side of the hind femora of 

 my two £ of D. nudus does not seem to be rubbed off; as, in both 

 sexes, the first joint of the antennae is tinged with red on the under 

 side, and as there are some other differences besides (which will be 

 seen by the comparison of the descriptions of both species), I am 

 led to the conclusion that there is a specific difference between D. 

 nudus and D. subciliatus. It is very striking how closely allied 

 the species of some groups of North American Dolichojms are. 



15. I*. s ill) c Hiatus, n. sp. % . — Viridis, nitidus, coxis anticis pedi- 

 busque flavis, ajjice tibiaruin posticaruni subfuseo, antennis tarsisque 



