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UNITED STATES NATIONAL MUSEUM BULLETIN 224 



with stout bristles but no spine. All tarsi end in long, 

 stout, moderately sharp claws, well developed pulvilli 

 and long, bladelike empodium. 



Wings: Marginal cell open, a distance equal to its 

 own width or slightly less. The anterior branch of the 

 third vein ends well above the wing apex ; the first sub- 

 marginal cell is open by a little more than its maximum 

 width. First posterior cell closed and stalked in many 

 species including the type of genus, but in some species 

 open. Fourth posterior cell closed and stalked. Anal 

 cell almost always closed in the margin. The ambient 

 vein is complete, the alula large. 



Abdomen: The abdomen is elongate and distinctly 

 tapered posteriorly ; at its base it is as wide as the mes- 

 onotum and is subcylindrical apically; it may be 

 slightly flattened over the basal tergites. Pile of abdo- 

 men abundant, quite short, fine, setate and appressed 

 except on the base of the basal tergites. Sides of the 

 first tergite with 5 to 8 long, stout bristles. There are 

 eight tergites in the male, the last being one- fourth to 

 one-fifth as long as the seventh; female with 8 tergites, 

 the last being one-half as long as the seventh. Male 

 terminalia rather prominent, characteristically not 

 rotate; the epandrium is completely divided, widely 

 separate; gonopod smaller; the hypandrium is promi- 

 nent, often long and may be sulcate apically. Female 

 terminalia with 6 pairs of conspicuous, stout, apically 

 rounded, spoon-shaped spines ; no lateral bristles below. 



Distribution: Nearctic: Scleropogon aeacid/'misWil- 

 liston (1886) ; bradleyi Bromley (1937) ; cinerascens 

 Back (1909) ; comanguineus Loew (1866) ; dispar 

 Bromley (1937) ; duncani Bromley (1937) ; ebyi Brom- 

 ley (1937) ; helvolus Loew (1874) ; indlstinctus Brom- 

 ley (1937) ; heUoggi Bi'omley (1937) ; latipennis Loew 

 (1866) ; longulus Loew (1866) ; neglectus Bromley 

 (1931) ; ochraceus Wulp (1870) ; plcticornis Loew 

 (1866) ; pumilus Coquillett (1904) ; similis Jones 

 (1907) ; subulatus Wiedemann (1828) ; tenebrosvs Co- 

 quillett (1904) ; texanus Bromley (1931) ; uhleri Banks 

 (1920). 



Neotropical : Scleropogon mexicanus Cole (1923); 

 truquii Bellardi (1861). 



Genus Neoscleropogon Malloch 



Figures 88, 184, 481, 897, 906, 1708, 1711, 1713, 1888, 2025 



Neoscleropogon Malloch, Proc. Linnean Soc. New South Wales, 

 vol. 53, p. 607, 1928. Type of genus: Dasijpogon elongatus 

 Maequart, 1846, by original designation. 



Bather large, elongate flies with cylindroid and 

 slightly tapered abdomen. They are characterized by 

 the generally short pile, which is long, fine and abun- 

 dant on the pleuron, the sternites and legs. The face is 

 narrow and the head is nearly circular from the anterior 

 aspect. Readily separated from Scleropogon Loew by 

 the fully rotate terminalia, which are not rotate in that 

 genus and in females by the winglike process to the 

 proctiger. Mesopleuron and lateral metasternum with 

 abundant pile in contrast to both Scleropogon and 



Stenopogon Loew. The prominent hypandrium is note- 

 worthy. Length 25 mm. 



Head, lateral aspect : The face is slightly visible on 

 the upper half, and moderately protuberant and 

 prominent below. The eye is recessive anteroventrally 

 beginning at the middle of the posterior eye margin. 

 The occiput is unusually prominent but slopes rapidly 

 backward from the eye margin; it is obliterated only 

 at the immediate vertex and at this point rapidly be- 

 comes thick and tumid. The occipital pile is fine, long 

 and crinkled and moderately abundant on the. lower 

 half. Occipital bristles begin at the midpoint of the 

 head and consist of 15 to 20 pairs of long, basally 

 stout, distally fine and strongly proclinate, black 

 bristles. Proboscis of moderate size, slightly com- 

 pressed dorsoventrally with a high, prominent, dorso- 

 medial, thinned ridge. The base is slightly swollen 

 laterally, the apex bluntly pointed, chiefly tapered from 

 below and bearing a prominent, lateral fringe of stiff, 

 long pile on the apical fifth which becomes shorter at 

 the extreme apex. The sides and ventral portion of 

 the proboscis on the basal half have some long, fine 

 pile. Palpus clearly of two segments ; the first segment 

 excavated and both segments with abundant, long pile; 

 the second segment is porate, with distinct, off-set at- 

 tachment and with the stiff pile more or less equallj 

 distributed on all sides except medially. The antenna 

 is attached at the upper third of the head, slender and 

 moderately elongate and of equal length with the head. 

 The first two segments are equal in length to the third, 

 if the microsegment is excluded. The third segment 

 is slender, slightly attenuate near the apex and bears a 

 long, subsegment which is attached obliquely but is 

 held in nearly the same plane; this subsegment is at 

 least half as long as the second antennal segment; to its 

 apex is attached a short, blunt, basally swollen spine. 

 The first segment bears numerous, long, stiff hairs 

 ventrally and laterally. Second segment with only a 

 few hairs ventrally and still fewer dorsally. 



Head, anterior aspect: The face is narrow, below the 

 antenna it is less than one-sixth of the head width and 

 divergent below. The face is micropubescent without 

 pile, but with two groups of prominent, long, slender, 

 pale bristles. There is a group arising from the flat- 

 tened portion of the face below the antenna which is 

 nearly as long as the third antennal segment and curved 

 downward, followed by a bare area in the middle of the 

 face. The entire medial portion of the facial protu- 

 berance is densely filled with very long, oblique, pale 

 bristles nearly as long as the antenna. Front slightly 

 divergent, with numerous, long, stiff hairs laterally or 

 weak bristles. The vertex is slightly excavated, the 

 ocellar protuberance moderately high, with steep sides 

 and bearing 8 to 10 pairs of long, weak bristles. An- 

 terior eye facets slightly enlarged. 



Thorax: The thorax is micropubescent laterally on 

 the mesopleuron and on the pleuron. The mesonotal 

 pile is moderately abundant, fine, erect and long. 

 Acrostical and dorsocentral elements are undifferenti- 

 ated from other pile except that before the scutellum 



