516 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 113 
Thorax uniformly cinereous with 2 longitudinal dark brown vittae 
near the center of the mesonotum and a broad broken dark vitta 
laterad from each of these; dorsocentrals 0+3; scattered setae on 
mesonotum; scutellum bare, except for 2 strong lateral bristles; 
propleural bristle strong; sternopleuron with 1 strong bristle near the 
upper hind margin and several short setae anterior to the bristle; long 
hairs on sternopleuron between the coxae; remainder of pleura bare; no 
prosternal bristles. 
Legs yellowish brown; middle tibiae with only 1 ventral apical 
bristle. 
Wings with brownish tinge, but no distinct infuscations; first vein 
joins costa at a level distinctly beyond the level of the anterior cross- 
vein; costal spines inconspicuous. 
Abdomen dark brown. 
FEMALE.—Similar to male, except that eyes are widely separated; 
cheek-eye ratio about 0.45. 
DistriputTion.—Alaska, Ontario, Quebec, Labrador; March, May, 
September. 
Genus Thelida Robineau-Desvoidy 
Thelida Robineau-Desvoidy, 1830, p. 655.—Schiner, 1864, p. 34.—Rondani, 1867, 
p. 129.—Pandellé, 1901, p. 343 (part). 
Heteromyza Fallén, Meigen, 1830, p. 45.—Macquart, 1835, p. 415 (part).—Loew, 
1859, p. 70.—Schiner, 1864, p. 33 (part).—Collin, 1901, p. 107 (part). 
Anthomyza Fallén, Zetterstedt, 1846, p. 1626 (part). 
Pegomya Robineau-Desvoidy, Meade, 1883, p. 9 (part). 
Heteromyiella Hendel, 1910, p. 309. 
This genus has been reported from North America (under the name 
Heteromyiella) on the basis of fossil evidence only. 
Thelida miocenica (Cockerell) 
Heteromyiella miocenica Cockerell, 1914, p. 644. 
This species was found by Cockerell in “Miocene shales of Floris- 
sant, Wilson Ranch (Wickham).’”’ One cannot accurately place the 
species from the information given, although Cockerell refers to the 
“short bristles on the costa,’’ which make it fairly certain that the 
specimens were heleomyzids. 
Genus Tephrochlamys Loew 
Helomyza Fallén, Meigen, 1830, p. 47 (part). 
Heteromyza Fallén, Macquart, 1835, p. 415 (part).—Zetterstedt, 1838, p. 763 
(part); 1847, p. 2461 (part).—Schiner, 1864, p. 33 (part).—Rondani, 
1867, p. 130. 
Tephrochlamys Loew, 1859, p. 72—Loew, 1862b, p. 128.—Aldrich and Darlington, 
1908, p. 71.—Czerny, 1924, p. 85; 1927a, p. 26—Collin, 1943, p. 241. 
Leria Robineau-Desvoidy, Pandellé, 1901, p. 344 (part). 
