TAXONOMY OF MUSCOIDFAX FLIES — TOWNSFXD 85 



snrne error the words "palpi black" were omitted from the descrip- 

 tion (Tr. Am. Ent. Soc, xix, p. 126). C. viola has palpi light 

 orange, and third abdominal segment is without discal macrochastas. 



Subfamily Thryptocerati.vl: 

 Genus Ceratomyiella Townsend 



Ceratomyiella conica Townsend. — This genus may be known by 

 the apical cell ending but slightly before wing-tip, usually if not 

 always short petiolate ; bend of fourth vein not sharply angular, 

 third vein bristly not quite to small crossvein, fifth vein not at all 

 bristly, and costal spine very small. The face is so elongate and 

 retreating in profile below eyes as to bring the insertion of vibrissas 

 nearly or quite into the transverse plane of the hind margins of 

 eyes ; the cheeks are one-third to one-half eye height in width 

 (nearly one-half in C. conica). 



Chcetoplagia has the apical cell narrowly open or closed in border. 



Metachceta greatly resembles Ceratomyiella in facial characters. 

 The facial profile is very receding and elongate below, so as to 

 bring the insertion of vibrissas close to or nearly into the transverse 

 plane of hind border of eyes (as viewed in full profile). 



ACRONARISTA, gen. nov. 



Allied to Schizotachina Walker, from which it is at once distin- 

 guished by the remarkable characters of the third antennal joint. 

 This is biramose in the female, being split into an anterior and a 

 posterior ramus, the two rami almost meeting apically and showing 

 in profile like an imperfect zero. The inner or under ramus is a 

 little widened apically ; otherwise the profile width of both is prac- 

 tically the same throughout, even including the base of the joint 

 where the rami join. The arista is inserted in the anterior edge of 

 the upper ramus well before its apex, but much nearer the apex than 

 the base, being at a distance from the apex equal to one-third the 

 length of the joint. The second aristal joint is only about twice as 

 long as wide, the first about as long as wide, and the third about 

 three times as long as second. Front equilateral, about one and 

 one-half times as wide as one eye, two middle fronto-orbital bristles 

 in female, facial plate very wide, parafacials reduced to a mere line, 

 facialia practically bare. Apical cell closed in margin near wing- 

 tip, last section of fourth vein bent in ; hind crossvein distinctly 

 nearer to small crossvein than to bend of fourth vein, but not nearly 

 so approximated to small crossvein as in Schizotachina. Third vein 



