326 Annals Entomological Society of America [Vol. XIII, 



Tetanocera Dumeril. 



Chcetomacera Cresson, Trans. Am. Ent. Soc, XLVI, 54 (1920). 



Cresson would discard the long established and well under- 

 stood Tetanocera, even though, he has not seen the original 

 paper of 1798, mentioned by Osten Sacken, basing his argument 

 upon a later and apparently different edition. As little is to 

 be gained by the overthrow of important names until every 

 doubt has been removed, the genus name Tetanocera will be 

 here retained in its accepted usage. 



Wing cells with brown cross-markings in addition to clouding of the cross- 

 veins; frontal orbits polished, interfrontal stripe reaching frontal 

 suture; hind femora with 2, rarely 3, extensor bristles 2 



Wings not lattice-marked, the crossveins clouded; frontal orbits usually 

 .subshining, interfrontal stripe stopping usually before the suture; 

 hind femora with 3 or more stouter extensor bristles 3 



2. Interfrontal stripe slightly wider anteriorly, parafrontal stripes extending 



but little in front of forward bristle; spots before second vein indis- 

 tinct, 5 spots in submarginal, 3 in first posterior cell, anterior part 

 of discal cell with 1 or 2 spots, hind crossvein oblique. N. H., Mass., 



N. Y., Ct., N. J.,* Pa., Md., Va clara Loew 



Interfrontal stripe with parallel sides, frontal stripes extending much 

 beyond anterior fronto-orbital; about 8 distinct spots in marginal 

 cell, 4 in first posterior, both sides of fifth vein with spots, posterior 

 crossvein more nearly perpendicular. Me., N. H., Vt., Mass., R. I., 

 Pa. (Hough), Queb., Cnt.,* N. Y., 111., Col.,* Wyo.* valida Loew 



3. Anterior margin of front shining and connected with 3 polished stripes; 



paramera biexplanate at tip; hind femora apically narrowly brown; 

 wings slightly infumated, crossveins browned, posterior crossvein 

 nearly straight; arista with long loose plumosity. Eur.,* Man. 



(Meigen, vSyst. Bes. VI, 41, 1830; Cresson, 65) silvatica Meigen 



Anterior margin of front dull; paramera more or less pointed, rounded, 

 or truncate 4 



4. Frontal orbits almost as wide as median stripe and polished, the median 



stripe continuing almost to the suture; hind femora of cf with 3 or 4 

 bristles in front and with the flexor spines not dense, of 9 with 2 such 

 bristles; thoracic vittae scarcely darker; third antennal joint triangular, 

 plumosity of arista moderately close; ocelli equidistant; posterior 

 crossvein little curved and rather perpendicular; scutellum nearly 

 devoid of setulse; paramera ham-shaped, the terminal part slender 

 and uncinate. Me., Mass.,* N. H., Vt.,* N. J., Ct., N. Y., Pa., D. C, 



N. Car., Queb., Ont.,* 111.,* Col., Mont*., Wash.,* B. C plebeia Loew 



Paraorbits only subshining, narrow 5 



5. Arista bushy-plumose, third antennal joint subtriangular, excised above, 



second joint with 2 or 3 long bristles above, of cf quadrate in outline, 

 of 9 somewhat longer; cervical spot distinct, with blackish center, 

 orbito-antennal spot black or brown, interfrontal stripe widest about 

 two- thirds its length and almost reaching suture, ocelli equidistant; 

 hind femora cT with 3 or 4 dorsal bristles and below densely bristly 

 and spinose, of 9 with 4 or 5 dorsal and 3 anterior bristles; costal 



margin infumated, posterior crossvein sinuate and oblique 6 



Plumosity of arista relatively less dense, third antennal joint less or not 

 at all drawn out; posterior crossvein arcuate or straight and less 

 oblique 8 



