Xylophagus triangularis Say 1823

Xylophagus triangularis Say
1823. Xylophagus triangularis Say, Jour. Acad. Nat. Sci. Phila., Ill, p. 30. 1908. Erinna triangularis Kertesz, Cat. Dipt., Ill, p. 137. .
This species has not been recognized since it was first described. Macquart 12 suspects this to be a Subula (Xylomyia) and Malloch (191 7: 348) states that he is convinced that Say's species is not a Xylophagus. Say however, states that the venation corresponds to that of Xylophagus ater Meig. Here follows Say's description :
"Black, sub-glabrous; thorax plumbeous with a black line; feet testaceous. .
"Inhabits Missouri.
"Body black; head pale plumbeous; antennae and palpi black; proboscis palerufous; trunk black polished; thorax, disk pale plumbeous, with a longitudinal polished black line, gradually and slightly dilating behind; nervures fuscous; hal teres white; feet testaceous, tips of the tarsi and of the posterior thighs and tibiae dusky; tergum polished with a large opaque triangle at the base of each segment excepting the first. Length two-fifths of an inch.
"The nervures of the wings are arranged in a similar manner with those of X. ater Fab. Meig."
12 Dipt. Exot., I., p. 171, (1838).