AMERICAN DIPTERA. 261 



i Front and face broad, with a hoary bloom suclator. 

 Front and face rather narrow, bloom upon them not hoary. 

 positivus. 



< Tibiae, except the tip, red 21. 



20, I Tibiae black 22. 



C Abdomen with a brush of black hair extending over the last 



three segments; pile along remaining segments ar- 



21. -I ranged in tufts aurifex. 



Abdomen without such a brush, segments 1-2 with pale yellow 

 pile not arranged in tufts pulcher. 



Scutellum polished black 23. 



Scutellum with gray pollen cretaceus. 



f Hairs on face mixed with some white, compare (longimanus) . 



Hairs on face yellowish; front tarsi of the male unusually long; 

 front and hind tarsi with silvery hairs on the upper 

 side princeps. 



22 .{ 



23. 1 



EASTERN SPECIES. 



Cyrtopogon alleni n. sp. 



9 . — Length about 14 mm. — Very close to lyratus, but larger and more 

 robust, and the pile of the posterior portion of the thoracic dorsum 

 and the scutellum is white, and the pleurae are wholly and densely 

 white pruinose. Pattern of thoracic dorsum distinct in a yellowish- 

 brown bloom; legs dark chestnut; wings distinctly clouded along some 

 of the veins. 



Polished black; face, except middle of gibbosity, frontal orbits and 

 occiput, white pruinose; pile of face nowhere as dense or long, nor 

 wholly black as in lyratus, but with many white hairs on the sides of 

 the gently rounded gibbosity. Antennae black, segment 3 more sud- 

 denly coarctate near the middle than in lyratus. Pile of basa] 

 segments of antennas, front and upper occiput black; of the lower 

 occiput, pronotum, meso- and sternopleura, before the halteres, on 

 the posterior portion of the dorsum and thinly on the scutellum white. 

 Pronotum, entire pleurae, spots on posterior callosities, lateral margins 

 of the first abdominal segment and the posterior lateral margins of 

 the abdominal segments 2-5 white pruinose. Bloom of pleurae is 

 dense, which is not the case in lyratus specimens that I have seen; in 

 these the bloom is confined to a stripe along the lower part of the 

 pleurae. Thoracic dorsum almost bare, with fine short black pile as 

 far back as the posterior callosities, from thence to and including the 

 scutellum with white pile, not very distinct, but not present in lyratus 

 The scutellum of lyratus has long black pile; of alleni, short white 

 pile. The markings of the dorsum are distinct in a yellowish-brown 

 bloom, as follows: — A broad pruinose stripe on each side extending 

 from the posterior callosities forward above the dorso-pleural suture 



TRANS. AM. ENT. SOC-, XXXV. JULY, 1909 



