INSECUTOR INSCITI^ MIlNSTRUUS 29 



Scutellum testaceous, except the black base, thinly silvery. 

 Abdomen shining black, thickly silvery-white pollinose on 

 bases of last three segments, the rest of surface showing thin 

 bloom in oblique light, anal segment bright rufous on posterior 

 half, a patch of obscure rufous on sides of second segment. 

 Venter wholly blackish, except the pale testaceous hind borders 

 of segments. Legs black. Wings clear. Tegulas white. 

 Holotype, No. 19600, U. S. Nat. Mus. TD435o. 



Neothelaira Townsend. 



Journ. N. Y. Ent. Soc. XX, 109-110 (June, 1912). 



Genotype, Masicera aurifrons Coquillett, 1897, Rev. Tach. 

 115 (Syn. Neothelaira dexina Townsend, 1912, 1. c, holo- 

 type. No. 19466, U. S. Nat. Mus., TD437). 



Front of female slightly exceeding one-third head-width at 

 vertex, widening rather evenly into face; that of male hardly 

 one-third same, with parallel sides on nearly posterior half ; 

 face about one and three-fourths times vertex in female, that of 

 male nearly twice vertex. Frontalia in middle a little narrower 

 than one parafrontal at same point. Parafacials broad, averag- 

 ing wider than length of second antennal joint. Front well 

 produced in profile, facial profile equal to or slightly longer 

 than frontal ; epistoma normally weakly prominent, not cut 

 ofif, slightly constricted, the vibrissae inserted a little above the 

 extreme oral margin. Vibrissal axis of head only a little 

 shorter than antennal axis, due to the strong bulging of occi- 

 put below ; the face very receding. Facialia practically bare, 

 only a few short bristles next vibrissse ; facial depression not 

 broad, rather long, shallow. Cheeks in both sexes nearly to 

 fully one-half eye-height. Outer verticals but slightly de- 

 veloped, strong pair of proclinate ocellars ; two proclinate and 

 two reclinate fronto-orbitals in female, three or four reclinate 

 in male ; five pairs of f rontals in female, seven or eight in 

 male, which descend to point below root of arista. Second 

 antennal joint moderately elongate; third narrow, about two 

 and one-half to three times second; arista not longer than 

 third antennal joint, well thickened on over basal half, tapered 

 rapidly, sharply pointed, basal joints short. Proboscis about 



