34 INSECUTOR INSCITI^ MENSTRUUS 



founded, although we consider the tanypezines less closely 

 related than are the other ortaline groups to each other. 



Among the peculiar tanypezine characters that seem to have 

 been overlooked thus far is a series of bristles on the halteres, 

 along the dorsal side of the stem. The males of several species 

 show on the hind legs small groups of spinelike bristles, on 

 the inner side of the trochanters and basally on the femora. 



Tanypeza luteipennis, new species. 



Shining black. Antennae black, the third joint broadly ovate, 

 pruinose. Proboscis yellow. Palpi black. Mesonotum with 

 a broad, weakly differentiated, pruinose median stripe which 

 involves the scuttellum, the humeri and sides to roots of wings 

 bright silvery pruinose; hairs yellowish, rather dense and 

 coarse, particularly on posterior half ; bristles black. Pleurae 

 with a broad silvery sericeous stripe from before roots of 

 wings onto upper part of mesosternum. Postnotum gray- 

 pruinose. Abdomen shining black, the hairs rather coarse, 

 yellowish, those at the sides, particularly on second segment, 

 black. Front coxse yellow, the others piceous on proximal 

 two-thirds. Legs yellow, the front femora somewhat infus- 

 cated dorsally^pn distal half ; front tibiae whitish ; tarsi blackish, 

 brown at baM', those of front legs with the proximal half of 

 the first joint whitish. Wings tinged with yellow, the venation 

 normal. Halteres white. 



Male. — Frons nearly one-fourth the width of head, broaden- 

 ing slightly on distal half. Abdomen with the hairs coarser, 

 more extensively black, the seventh segment dorsally silvery 

 pruinose. Hind femora near base with a small group of short, 

 black, spinelike bristles dorsally on inner aspect, a similar 

 group on inner side of trochanters. 



Female. — Frons one-fourth the width of head, parallel-sided. 

 Abdomen with the apical margin of the sixth segment broadly 

 whitish. 



Length : Body about 5.5 mm., wing 5 mm. 



Algonquin, Illinois, 6-7-95, 1 male, 1 female (collection 

 Coquillett) ; Franconia, New Hampshire, 1 male, 3 females 



