452 NORTH AMERICAN DIPTERA 



312. Eyes quite bare; ultimate section of fifth vein only about half as long 



as the preceding section 315 



Eyes with short, sparse hair; apical section of fifth vein two-thirds 

 as long as preceding section (97, 98) Stomatomya Rondani 



313. Apical cell open or closed in the wing margin 317 



Apical cell closed and petiolate 314 



314. Arista almost wholly thickened 315 



Arista slender on apical fourth or more. 



Anacheetopsis Brauer & Bergenstamm 



315. Arista slender on apical half or more Phceniceomyia Townsend 



Arista almost wholly thickened 316 



316. Penultimate aristal segment four times as long as wide (114). 



Chaetoglossa Townsend 

 Penultimate aristal segment not twice as long as wide. 



Archiclops Bischoff 



317. Proboscis shorter than the head-height 318 



Proboscis twice as long as the head-height; aristal segments of almost 



equal length Eucoronomyia Townsend 



318. Males 319 



Females 332 



319. Orbital bristles present although sometimes situated almost in the 



frontal row 320 



Orbitals absent 325 



320. Abdomen with discals, not unusually deep 321 



Abdomen without discals, elongate and deep; antennae arising below 



the middle of the eyes; two pairs of presutural acrosticals and dor- 

 socentrals Chaetonodexodes Townsend 



321. Anterior tibise with two or three strong posterior bristles 323 



Anterior tibiae with a single posterior bristle 322 



322. Third antennal segment divided into two lobes Schizotachina Walker 



Third antennal segment entire, not unusually wide. . .Celatoria Coquillett 



323. Frontal vitta wider anteriorly than the least width of either para- 



frontal " 324 



Frontal vitta nowhere wider than the least width of either para- 

 frontal, not widening anteriorly Paralispe Brauer & Bergenstainm 



324. Front almost or quite as wide as either eye Racodineura Rondani 



Front less than two-thirds as wide as either eye (Arrhinomyia B. B.) 



(149, 173) *Elodia Desvoidy 



325. Second antennal segment not unusually bristly above but with some 



longer bristles apically 326 



Second antennal segment densely bristled above; facial ridges with 

 bristles on more than the lower half (9) fTachinomyia Townsend 



* Villeneuve and Aldiich (1929, 1933) recoprnize Arrhinomyia as distinct from Elodia but 

 I see no reason for this. 



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



