FAMILY TACHIXID.E — THE TACIIIXIDS 453 



326. Anterior tibiae with at least two posterior bristles; species over 5 mm. 



in length 328 



Anterior tibiae with a single posterior bristle; species about 4 mm. 

 in length 327 



327. Apical cell ending very close to the wing-tip Oxynops Townsend 



Apical cell ending far before the wing-tip Bessa Desvoidy 



328. Abdomen tapering or not, often with discals; posterior forceps split 



on apical portion, nev^er laterally compressed 329 



Abdomen elongate, tapering, rarely with discals; posterior forceps of 

 male united into a long, compressed organ (9) .*Tachinomyia Townsend 



329. Apical scutellars cruciate 330 



Apical scutellars absent or divergent 331 



330. Antennae reaching slightly beyond the oral margin, the third segment 



at least six times the length of the second (Europe). .Frontina Meigen 

 Antenna not reaching the oral opening; third segment not over four 

 times the length of the second Allophorocera Hendel 



331. Parafacials wide, the cheeks two-thirds as wide as the eye-height, 



the parafacials setulose on the upper half Centeter Aldrich 



Parafacials narrower, the cheeks less than one-third the eye-height. 



Degeeria Meigen 



332. Genital opening not slit-like; abdomen broader than deep 334 



Genital opening slit-like; abdomen broad and deep 333 



333. Orbitals scarcely divergent; abdomen rarely with discals (9). 



*Tachinomyia Townsend 

 Orbitals conspicuously divergent; abdomen always with discals. 



Allophorocera Hendel 



334. Third vein with a single strong basal bristle 339 



Third vein with two or more basal bristles 335 



335. Arista pubescent or bare; third vein with not more than five bristles 



basally 336 



Arista short plumose; third vein bristled almost to the small crossvein. 



Paralispe Brauer & Bergenstamm 



336. Parafacials almost as wide as the median depression, setulose on 



almost the upper half Centeter Aldrich 



Parafacials narrower, bare below the lowest f rontals 337 



337. Penultimate aristal segment very elongate. 



Trichopareia Brauer & Bergenstamm 

 Penultimate aristal segment short; abdomen with or without short 

 discals; two sternopleurals 338 



338. Middle tibiae with two strong anterodorsal bristles. Frontiniella Townsend 

 Middle tibise with only one strong anterodorsal bristle. Oxynops Townsend 



339. Lower margins of the second tergite strongly produced downward and 



with numerous spinose setulse; ovipositor long and slender, often 

 hidden Celatoria Coquillett 



* Curran, 1926, Tr. Roy. Soc. Canada, Sec. V, p. 168. 



