FAMILY TACHIXID.E THE TACHIXIDS 445 



211. Penultimate aristal segment nearly three times as long as wide. 



Acronaristopsis Townsend 

 Penultimate aristal segment less than twice as long as wide. 



Minthoplagia Townsend 



212. Posterior sublateral bristle present 225 



Posterior sublateral bristle absent 213 



213. Penultimate aristal segment not over twice as long as wide 214 



Penultimate aristal segment and the preceding one more than twice 



as long as wide Ostracophyto Townsend 



214. Oral margin strongly produced; face never carinate 215 



Oral margin not or but little produced; face sometimes carinate 217 



215. Abdomen broad and thick; robust species, usually with four post- 



sutural dorsocentrals; three or more sternopleurals 21G 



Abdomen elongate and narrow; three sternopleural and three pairs of 

 postsutui-al dorsocentrals Eriothrix Meigen 



216. Normally only three postsutural dorsocentrals; parafacials almost 



as wide as the length of the third antennal segment. 



Metaphyto Coquillett 

 Four postsutural dorsocentrals; parafacials narrower than width of 

 third antennal segment Ernestia Desvoidy 



217. Posthumeral bristle present; bend of fourth vein sub-angulate 218 



Posthumeral bristle absent 222 



218. Two sternopleurals, rarely a very weak third 221 



Three stei'nopleurals; male abdomen strongly produced apically 219 



219. Apical cell ending very close to the wing-tip Cleonice Desvoidy 



Apical cell ending far before the wing-tip 220 



220. Prosternum with bristly hairs 224 



Prosternum bare (65, 66) *Uramya Desvoidy 



221. Prostemiim bare (178, 184) fPseudeuantha Townsend 



Prosternum haired; lower squamal lobe haired above toward the outer 



edge; large, I'obust, tropical species Tropidopsis Townsend 



222. Third abdominal segment with two or three arched rows of long 



discals Grisdalemyia Curran 



Third abdominal segment with one or two pairs of discals; pro- 

 sternum bare 223 



223. Three sternopleurals 224 



Two sternopleurals JHyalurgus Brauer & Bergenstamm 



224. Discals present on second to fourth abdominal segments. 



Xanthocera Townsend 

 Discals absent Euthelairopsis Townsend 



225. Second antennal segment usually less than half as long as the third. .227 

 Second antennal segment almost as long as the third 226 



* Aldrich, 1921, Ins. Ins. Mens., ix, p. 85. 



t Aldrich, 1921, Ins. Ins. Mens., ix, p. 87. 



t Pseudeuantha may trace here but has white haired pleura. 



