SCELLUS. 20'.) 







the middle of the last segment of the fourth longitudinal vein there 

 is a gray-blackish spot of considerable size. 



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



4. S. filiferus, nov. sp. . Thoracis dorso cinereo, opaco, abdomine 

 cupreo, cinereo-pollinoso, subopaco, halteribus albidis, alls hyalinis in 

 basi subalbidis, apicem versus cinereo-striatis punctisque duobus nia- 

 jusculis nigricantibus, altero didymo in vena transversa posteriore, 

 altero simplici in ultimo venae longitudinalis quartse segmento ; lamellis 

 analibus maris augustissimis albis, in basi nigris, in summo apice fla- 

 vicantibus. 



Upper side of the thorax gray, opaque ; abdomen copper-colored with gray- 

 ish dust, rather opaque ; halteres whitish ; wings hyaline, whitish near 

 the root, with gray stripes towards the tip ; upon the posterior transverse 

 vein with a double blackish spot of considerable size, and with a simi- 

 lar, but single spot upon the last segment of the fourth longitudinal 

 vein ; the anal appendages .of the male are very narrow, white, black at 

 the basis and yellowish at the extreme tip. Long. corp. 0.15. Long, 

 al. 0.20. 



The narrow face is ochre-yellow. Antennas black. Front with 

 white dust. Thorax blackish bronze-colored with copper-colored 

 reflections ; on the upper side with thick whitish dust, which 

 almost conceals the ground-color, opaque ; upon the pleurae with 

 a somewhat thinner dust of the same color. Upon the middle of 

 the upper side there are two narrow parallel lines of a darker 

 color, which do not reach as far as the posterior margin of the 

 thorax. The scutellurn, which has -two bristles, is of the same 

 color as the pleura?. The ground-color of the abdomen is like 

 that of the thorax, is, however, more distinct, not being so thickly 

 covered with dust ; towards the lateral margin of the abdomen, 

 where the dust almost entirely disappears, there is a bright cop- 

 per-colored lustre. The anal appendages of the male, which are 

 turned upwards at their tip, are not ribbon-like, as in the pre- 

 viously described three species, but filiform, white, black at the 

 root, at the tip pale-yellowish to a small extent ; on the middle of 

 their exterior margin there is a dense beard of delicate little white 

 hairs ; there is no tuft of hairs at their tip. Between them, in the 

 anal region, only a moderate number of short delicate little hairs, 

 which may be easily overlooked, are inserted. Coxae of a black- 

 ish-bronze color with whitish dust ; the fore coxa? have, besides 

 14 



