68 PROCEEDINGS OF THE NATIONAL MUSEUM vol. GS 



spicuous tuft of black hairs on the heel and fringing the outside; 

 middle tibia with the usual single bristle on the outer front side near 

 the middle and a row of four to five uneven bristles on the outer 

 hind side. 



Female. — Front at narrowest 0.43 of the head width (measure- 

 ments of two 0.42 and 0.44 respectively) ; front somewhat more 

 golden pollinose, without the conspicuous dark reflections; two 

 rather strong proclinate orbitals differentiated from the surrounding 

 bristles and bristly hairs on the parafrontals ; vibrissae at least the 

 length of the second antennal joint above the front edge of the oral 

 margin; third antennal joint equals two and one-half times length 

 of second; in profile, bucca equals one-third eye height. Thorax 

 densely golden bronze pollinose; sparsely short setulose. Abdomen 

 black, densely covered with golden bronze pollen, without a broad 

 black median vitta; a pair of small but distinct bronzed spots towards 

 the sides on the first three segments, fourth pollinose to apex. Front 

 basitarsus without modifications. Otherwise except for usual 

 differences of genitalia, like the male. 



Length 5.0 to 6.0 mm. 



Ti/pe.— Male, Cat. No. 19554. U.S.N.M. 



Redescribed from the type, a male specimen from London Hill 

 Mine, Bear Lake, British Columbia, 7,000 feet, July 21, 1903 (J. W. 

 Cockle) ; two females and one male, Marshall Pass, Colorado, Jul}^ 

 18, 1908, 10,856 feet; one female, Tennessee Pass, Colorado, 10,240 

 feet (J. M. Aldrich) ; all in the collection of the National Museum. 



This Rocky Mountain alpine form has as yet not been collected 

 below 7,000 feet elevation. Little is known of its habits and nothing 

 concerning the host relationships. 



Genus PHROSINELLA Robineau-Desvoidy 



Phrosinella Robineau-Desvoidy, Dipt. Envr. Paris, vol. 2, p. 83, 1863 

 Genotype (Tachina) nasida Meigen from Europe. 



Phrosina Robine.\u-Desvoidy, Dipt. Envr. Paris, vol. 2, p. 101, 1863. 

 According to Bezzi and Stein, Kat. Pal. Dipt., vol. 3, p. 513, 1907, pre- 

 occupied, and the genotype argyrina Robineau-Desvoidy equals nasuta 

 which is the genotype of Phrosinella. 



Euhilarella Townsend, Proc. Biol. Soc. Wash., vol. 28, p. 22, 1915. Geno- 

 type Hilarella fulvicornis Coquillett. 



Inner orbits narrowest at base of antennae, diverging moderately 

 toward vertex and bucca but distinctly pinched in at tlie lower 

 comers of the eyes; front distinctly narrower in males than in females: 

 frontal vitta strongly divergent posteriorly, at middle wider than 

 parafnmtals, usually with distinct wrinkles radiating from base of 

 antennae; a single row of frontal bristles which extends below base 

 of second antennal joint and is suddenly divergent below; orbital 

 bristles, usually one reolinate and tvro proclinate, present in both 



