250 tut CANADIAN ENTOMOLOGIST. 



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

 ground, subshining on the lower part that is covered with black hairs, a row 

 of stouter hairs or bristles at the oral margin. Distance from the oral margin 

 to the base of eye equal to about one-third the eye height. Sides of face covered 

 with silvery pollen ; bare ; narrowest width equal to the length of the second 

 antennal segment. Facial ridges bristly on the lowest fourth. Facial 

 depression silvery pollinose, without any carina. Antennae reaching the 

 lowest fourth of the 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 penultimate section scarcely longer than broad. Width 

 of front at narrowest point measuring slightly greater than the length 

 of the second antennal segment, the front silvery pollinose; frontal vitta 

 dull, dark-brown, at narrowest point slightly wider than either side of front 

 just cephalad of the ocellar triangle. No orbital bristles, the ocellars proclinate; 

 the single row of frontal bristles extending nearly to the base of the third an- 

 tennal segment. 



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

 pollinose on a black ground that is very slightly reddened at the apex. Three 

 sternopleural bristles and four pairs of dorso-centrals. Scutellum witli three 

 pairs of marginal 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; R,j+5 (third vein) with a group of five to ten hairs both above and be- 

 low at the junction with R2+3. Tegulae white. 



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

 median marginal macrochaetae on segments two, three and four. The hind mar- 

 gin of the third tergum slightly arcuate. The fifth tergum which is pollinose, 

 clearly marked off from the sixth which is shining; the fifth tergum is at its 

 greatest length about one-fifth the length of the lateral part of the fourth. The 

 sixth and seventh abdominal segments form the somewhat distended genital 

 segments. 



Male genitalia black. The basal part of the outer forceps is expanded 

 into a broad, leaf-like portion. The basal part of the inner forceps is equipped 

 with a short median, keel-like projection, the basal edge of which is very slightly 

 concave in profile. 



The horseshoe-like indenture extends a little less than half way to the 

 base of the fifth sternite. The outer edges of the prongs are deeply incised, 

 thus affording a character that serves to separate the species from any other 

 North American species. 



Described from a single male taken at Carlisle Junction, Pa., by W. R. 

 Walton. 



Type No. 24356 in the U. S. National Museum, Washington, D. C. 



Ernestia aldrichi Town. 



Head at vibrissae about as thick as at base of antennae; viDrrssae w^ell 

 above the oral margin. Palpi dusky yellow to almost black. Eyes hairy. 

 Cheeks (below the eyes) white pollinose on a black ground, subshining on 



