FAMILY TACHI.XID.E — THE TACHIXIDS 



463 



At most two pairs of strong: presutural acrosticals, the posterior pair 

 not situated very close to the suture (132) Chjetona Wulp 



468. Arista wholly thick, taperin<2: apically Phantasiomyia Townsend 



Arista slender apically 469 



469. Genital opening: ventral, not visible from behind. . . Panacemyia Townsend 

 Genital opening apical, visible from behind 470 



470. Frontal vitta linear (very narrow in ? ?) Arsyrochaetona Townsend 



Frontal vitta wide 471 



471. Anterior tibise with a single posterior bristle 473 



Anterior tibiae with two posterior bristles 472 



472. Small slender species, under 5 mm. (149, 173) Elodia Desvoidy 



Larger, robust species, over 6 mm • Calothelaira Townsend 



473. Frontal vitta twice as wide as the parafrontals, not at all narrowed 



medianly; anterior tibiae without a conspicuous posterodorsal 



bristle (181, 193) Microtownsendia, n. g. 



Frontal vitta narrower than either parafrontal; anterior tibiae with a 

 single conspicuous posterodorsal bristle situated near the middle. 



Tachinophyto Townsend 



Scotiptera melaleuca. 



