THE CANADIAN ENT0MOLX)GIST 229 



marginal pairs of macrochaetae and an apical cruciate pair. Legs black, the 

 middle tibiae with two or more bristles on the front side near the middle, the 

 hind tibiae without a comb-like row of bristles on the outer side. Wings 

 hyaline. R4+r, (third vein) with a group of two to five hairs both above and 

 below at the junction with R2+:;- Bend of Mj^. with an appendage. An un- 

 usually long costal spine. Tegulae white. 



Abdomen subshining; silvery pollinose on a black ground. Discal and mar- 

 ginal macrochaetae present on the second, third and fourth abdominal segment. 

 The hind margin of the third abdominal segment not arcuate. The fifth tergum 

 marked ofl: distinctly from the shining sixth, and at the lateral part being about 

 one-fifth the length of the lateral part of the fourth. The sixth and seventh 

 abdominal segments forming the not very prominent genital segments. 



Genitalia black. The basal part of the outer forceps without a leaf-like 

 expansion. The basal part of the inner forceps without a median keel-Hke 

 portion. 



The horseshoe-like indenture extends almost to the base of the last 

 sternite. 



Described from two males from Yukon River, Alaska, and Cranbrook, 

 B.C., taken by Messrs. Harrington and C. Garrett. 



Type Number 24,352 in the U.S.N.M., Washington, D.C., the paratype 

 in the Canadian National Collection, Ottawa. 



Ernestia johnsoni sp. n. 



Description of Male. Head at vibrissae about as thick as at base of 

 antennae; vibrissae far above the oral margin. Palpi yellow in the type 

 material. Eyes hairy. Cheeks (below the eyes) white pollinose on a black 

 ground with black hairs coming nearly up to the eyes and with a row of 

 stouter hairs at the oral margin. Distance from the oral margin to base of the 

 eye equal to about one-third the eye height. Sides of face silvery pollinose; 

 bare; narrowest width of the front slightly greater than the length of the 

 second antennal segment. Facial ridges bristly on lowest fourth. Facial de- 

 pression silvery pollinose without any carina. Antennae reaching the lowest 

 fourth of face, all three segments black; third segment about one and one-half 

 times as long as the second. Arista thickened on basal two-fifths, the penulti- 

 mate segment scarcely longer than broad. Width of front at narrowest point 

 measuring a little more than the length of the second antennal segment; the 

 front silvery pollinose; frontal vit-ta dull, dark-brown; at narrowest point about 

 twice as wide as either side of the front immediately cephalad of the oceillar 

 triangle. No orbital bristles, the proclinate ccellars somewhat weak; the single 

 row of frontal bristles descending nearly to the base of the third antennal 

 segment. 



Thorax subshining, black, covered with gray pollen ; scutellum gray 

 pollinose on a black ground, in most specimens tinged reddish, especially at 

 the apex. Typically three sternopleural bristles, but they are variable; typically 

 four dorsocentral macrochaetae, some specimens with only three ; scutellum 

 with three marginal pairs of macrochaetae and with an apical cruciate pair. 

 Legs black, the middle tibiae with two or more bristles on the front side near 

 the middle, the hind tibiae without a comb-like row of bristles on the outer 



