170 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



eral, 6 lateral apical, 6 medial apical, and 2 dorsal; 

 in addition there are 2 dorsal subapical bristles. This 

 tibia bears 4 ventrolateral bristles, beginning before 

 the middle, 7 dorsolateral, and 8 dorsomedial; and 

 the apex has 1 dorsal, 3 lateral, 5 ventral, and 2 medial 

 bristles. Middle femur with a posterodorsal and sub- 

 apical cluster of 10 bristles, 5 or 6 anteroapical, and 

 2 anterior bristles in the middle; its tibia has bris- 

 tles similar to the hind pair. Anterior femur similar 

 to the middle femur in respect to the cluster of bristles. 

 Anterior tibia with 7 anterodorsal, 5 posterodorsal, 

 6 rather longer, stout posterior bristles; the apical 

 bristles are especially stout and long, 10 in the circle 

 and no spine present. All tarsi with sharp claws, 

 long, spatulate pulvilli and long, basally thickened 

 empodium. 



"Wings: The marginal cell of the wings is widely 

 open; the anterior branch of the third vein ends just 

 before the wing apex; posterior branch ends well be- 

 hind the wing apex. All posterior cells widely open ; 

 anal cell closed in the margin; second basal cell ends 

 in three veins; alula moderately long; ambient vein 

 complete ; wings hyaline. 



Abdomen : The abdomen is comparatively short and 

 robust, a little shorter than the wing; the abdomen is 

 as wide as the thorax basally, bare and shining with 

 prominent, pollinose, posterior fasciae on the tergites. 

 Male with seven tergites, the seventh one-fourth as long 

 as the sixth. Female with eight tergites, the eighth 

 very short and only a fifth as long as the seventh which 

 is also a little shortened. Pile of abdomen dense but 

 fine, suberect, a little longer on the sides of the first 

 two tergites. First tergite with 6 or 7 weak bristles 

 laterally. Male terminalia rotate one-fourth to the 

 left. Epandrium divided into superior forceps. Hy- 

 pandrium very short. The gonopod is moderately long, 

 bearing as in Ceraturgus a dense tuft of long, fine pile. 

 Female acanthophorites with spines. 



Distribution: Nearctic: Ceraturgopsis cornutus 

 Wiedemann (1828); oklahomensis Bromley (1934). 



Genus Cyrtopogon Loew 



Figures 116, 531, 1038, 1047, 1827, 1850, 1982 



Cyrtopogon Loew, Linnaea Entoniologiea, vol. 2, p. 516, 1847. 

 Type of genus : Asilus ruficomis Fabricius, 1794. Designated 

 by Rondani, 1856, tbe first of four species. 



Euarmostus Walker, Insecta saundersiana, vol. 1, pt. 2, p. 102, 

 1851. Type of genus: Euarmostus bimacula Walker, 

 1851, by monotypy. 



Euarmostus Walker, List . . . dipterous insects . . . British 

 Museum, suppl. 2, p. 423, 1854, lapsus. 



Pliilammosius Rondani, Dipterologiae italicae prodromus, vol. 

 1, p. 156, 1856. Type of genus : Dasypogon flmoriatus 

 Meigen, 1820, by original designation. Kertesz and Engel 

 both place Pliilammosius Rondani in synonymy under 

 Stirhopogon Loew ; however, Engel places the type of genus, 

 Dasypogon fimhriatus Meigen, in synonymy under Cyrto- 

 pogon lateralis Fallen. 



Cyrtopogon has 1 subgenus, Pdlamopogon Bezzi. 

 Medium size flies ranging from very short pilose 

 species with the abdomen almost entirely bare and 



pollinose, at least along the posterior margins, to species 

 in which thorax, abdomen, head, and femora are 

 densely, long pilose. The face is characteristically 

 protuberant and rounded both from lateral and dorsal 

 profiles, retreating above to the antenna and below 

 to the ocular margins and characteristically covered 

 with dense, long pile ranging from fine to stiff, slender 

 bristles. The head is wide, the eyes flattened. The 

 third antennal segment is slender with at least two 

 obliquely directed microsegments. All marginal cells 

 open and secondary sex characters or ornaments fre- 

 quent, especially on the tarsi. Length 9 to 22 mm. 



Head, lateral aspect : The face is conspicuous, gently 

 rounded and protuberant, retreating to the antenna 

 above and to the epistomal margin below. The eye is 

 of moderate length, the anterior profile oval; the eye 

 is moderately recessive anteroventrally and slightly 

 flattened near the facial margin. The occiput is prom- 

 inent especially on the lower half due to the recession of 

 the eye; it is nearly obliterated near the vertex. Pile 

 of occiput abundant, long and fine, especially dense 

 on the lower half. Dorsal bristles may be absent but 

 in the type of genus near the vertex there are numerous, 

 strongly proclinate, long, slender, bristly hairs. The 

 proboscis is short, in the type of genus only slightly 

 projected beyond the face, obtusely rounded at apex 

 and distinctly widened laterally towards the base. In 

 some species it is shorter than the face, not widened at 

 the base and somewhat more obtuse at the apex; the 

 proboscis carries fine, short, stiff hairs at the apex and 

 abundant, long, fine pile at the base; medial ridge ab- 

 sent; it is usually directed obliquely forward. Palpus 

 clearly of two segments; first segment excavated, second 

 segment porate, rather slender, slightly attenuate, with 

 some fine, bristly pile extending on to the apex but 

 chiefly dorsal in character. 



The antenna is attached at the upper third of the head 

 and is comparatively long and slender and slightly 

 shorter than the head. The first two segments of nearly 

 equal length, the first generally a little longer. The 

 third segment is nearly twice as long as the first two 

 combined and tends to be slightly and gradually ex- 

 panded over the middle ; it is a little narrowed at the 

 apex, which bears two microsegments. The first micro- 

 segment is quite short ; the second is longer and may be 

 a sixth to a third as long as the third segment proper. 

 The ultimate microsegment is held characteristically 

 at an oblique angle, its apex bears a minute, short, dis- 

 tinct spine. The pile of the first consists of long, stiff, 

 subappressed, bristly hairs; second segment with 

 similar but fewer hairs but usually with at least one, 

 sometimes several, long, stiff, oblique, stout bristles; 

 third segment dorsally with a few appressed, short 

 bristles. 



Head, anterior aspect: The face below antenna less 

 than one-third the width of head and slightly divergent 

 below. The subepistomal area is moderately large, 

 oblique, concave, with a deep ocular recess or crease on 

 either side along the eye margin. The face is densely 

 pubescent and everywhere, except along the immediate 





