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UNITED STATES NATIONAL MUSEUM BULLETIN 2 24 



teriorly. Humerus short pilose, moderately stout ; long, 

 lateral bristles present as follows: 1 notopleural, 1 post- 

 supraalar, 1 postalar, no scutellar bristles. Scutellum 

 quite flat or slightly concave, with abrupt margin; 

 surface pollinose and only the margin with fine, erect 

 pile. Propleuron with abundant, fine pile; pronotum 

 with pile only. Posterior mesopleuron with a band 

 containing about 20 fine, subappressed hairs. Upper 

 posterior sternopleuron with a patch of pile. Meta- 

 pleuron with a single, vertical row of 9 quite long, mod- 

 erately stout, fanlike bristles. Metanotal slopes pubes- 

 cent only. Lateral slopes of metasternum without pile. 

 Postmetacoxal area membranous. 



Legs: The hind femur and tibia slender and some- 

 what elongate, the anterior and middle femora more or 

 less thickened, especially the anterior pair. Femora 

 and tibiae pollinose except below; the hind femur is 

 densely, finely, appressed set ate and with a short bristle 

 at the apex dorsally on either side ; 6 bristles in the lat- 

 eral row, 2 quite long, moderately stout, ventral bristles, 

 one near the base, and the other one before the middle. 

 The hind tibia has 4 dorsal, 1 dorsolateral in the middle, 

 2 rather stout, long, curved, ventrolateral bristles. The 

 apex has 6 bristles. Middle femur with 1 stout bristle 

 anteroapically, another anteriorly at the outer third; 

 this tibia has 4 dorsal, 2 anterior, 1 at the middle quite 

 long and curved and 4 posterior, and 2 ventral bristles 

 exceptionally long and stout and oblique. Anterior 

 tibia with 3 or 4 dorsal and 3 quite long, stout, posterior 

 bristles, the apex with 6 bristles and no spine. Apical 

 bristles of the first 3 tarsal segments exceptionally long 

 and stout ; all tarsi end in long, slender pulvilli, a long 

 empodium, and sharp, slender claws. 



Wings: The anterior branch of the third vein ends at 

 wing apex, but is pulled backward; the posterior 

 branch ends well behind the wing apex. All posterior 

 cells open, the fourth narrowed to one-half its width; 

 anal cell closed and stalked ; second basal cell ends in 2 

 veins and is fused beyond. Alula narrow and linear; 

 the ambient vein complete. 



Abdomen: The abdomen is dorsoventrally com- 

 pressed, flattened, with parallel sides to the end of the 

 fourth tergite, slightly tapered or narrowed beyond. 

 Pile of abdomen quite short and erect. Bristles re- 

 stricted to the first tergite; 6 or 7 weak bristles present. 

 Eight tergites well developed in the female. On the 

 female terminalia the acanthophorites bear 4 or more 

 pairs of long, spatulate, thin spines; basal plate pro- 

 duced posteriorly into a lateral, more or less rounded 

 flap. 



Subgenus Cryptopogon White 



Figubes 61, 446, 895, 904, 1596, 1691, 1692, 1942, 2029 



Cryptopogon White, Papers Proc. Royal Soc. Tasmania, p. 76, 

 1917. Type of subgenus : Cryptopogon vernaculus White, 

 1917, by monotypy. 



Small, pale pollinose flies which are very similar to 

 Stichopogon Loew and differ principally in the presence 

 of a crossvein between the second vein and the base of 

 the anterior branch of the third vein. This crossvein 



is apt to be absent in some individuals of the species. 

 Length 4 to 6 mm. 



Head, lateral aspect: The head length is moderate, 

 the eye strongly convex anteriorly. The occiput is 

 prominent and thick below, and obliterated near the 

 vertex. Pile of occiput fine over the middle and below ; 

 upper occiput with a row of short, bristly hairs. The 

 face is scarcely visible in profile, a little more prominent 

 below. Covered with micropubescence, the lower part 

 of face has a short patch of dense, moderately fine, 

 bristly hairs which consist of 25 to 30 pairs; sides of 

 subepistoma with a row of 8 fine hairs. The proboscis 

 is wide, short, blunt, cylindroid, with a few hairs at 

 apex and numerous, long, fine hairs at the base below. 

 The palpus is composed of two segments, is extremely 

 slender, cylindroid, with a sharp apex ; second segment 

 apilose. The antenna is attached at the upper third of 

 the head and similar to Stichopogon in structure. 



Head, anterior aspect: The face below the antenna is 

 narrow and considerably expanded below. The front 

 is long, with 3 or 4 fine, short hairs on each side. The 

 low ocellarium has 4 or 5 fine bristles and 2 long, stiff 

 bristles. The vertex is scarcely excavated and is 

 shallowly concave. 



Thorax : The mesonotum is comparatively low with 

 thick, fine, suberect microsetae. The following bristles 

 are present : 1 on the notopleuron, 1 on supraalar, 1 on 

 postalar; the flattened scutellum with no bristles but a 

 number of fine hairs on the margin. Humerus pilose, 

 the disc without pile. The pleuron is micropubescent, 

 the propleuron pilose, postmargin of the upper meso- 

 pleuron with a few minute, short hairs; pteropleuron 

 and hypopleuron bare ; metapleuron with a vertical row 

 of erect, long, slender bristles. Metanotal slopes with- 

 out pile; postmetacoxal area membranous. 



Legs: The anterior femur is distinctly thickened; 

 posterior femur only slightly thickened. Hind femur 

 with a row of 3 dorsomedial bristles near the apex, a row 

 of 5 central and dorsolateral bristles, and 1 bristle near 

 the base and apex; ventromedially this femur has a 

 fringe of long, fine pile; elsewhere densely microsetate. 

 Hind tibia with 3 dorsal, 4 lateral, 3 ventral bristles 

 and at the apex with 1 dorsal, 2 long lateral, 3 medial, 

 and 2 ventral bristles. Midfemur with 3 anterior 

 bristles situated near apex in a row. Midtibia with 2 

 or 3 long anterior, 2 or 3 short dorsal, and 2 ventral 

 bristles; apex with 1 posterior, 1 anterior, 1 ventral 

 bristle. Anterior femur with 2 small subapical dorsal 

 bristles ; anterior tibia with 3 short posterior, 4 ventral, 

 2 short basal, 2 long distal bristles; apex with 1 long 

 anterior, 2 short dorsals, 1 long medial, 3 short ventral ; 

 no spine present. All tarsi end in well developed pul- 

 villi, long unthickened empodium and sharp claws. 



Wings : Venation of wings similar to Stichopogon but 

 with a short, vertical crossvein present between the 

 second vein and the base of the anterior branch of the 

 third vein. 



Abdomen : The abdomen is more or less flattened and 

 wulened and only slightly to moderately convex across 

 the tergites; it is as wide as the thorax at base and 



