208 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



pale micropubescence, the upper third without pile; 

 lower gibbous portion with a cluster of 12 to 14 mod- 

 erately long, basally stout, yellow bristles, together with 

 numerous, more slender bristles below on each side and 

 with a few fine, shorter hairs above the bristles. Front 

 slightly widened across the middle, narrowed above to 

 approximately the same width as that across the an- 

 tenna. Vertex shallowly excavated, the ocellarium 

 large and rounded and bearing 2 stout, long bristlesin 

 the center and several fine, long hairs behind. Anterior 

 ocellus enlarged. On the sides of the face on the bottom 

 of the eye there is a deep, conspicuous, recess or pocket 

 quite suggestive of Plesiomma Macquart. 



Thorax : The thorax is pollinose, with down the mid- 

 dle a divided row of fine, erect hairs and with 4 long, 

 slender, dorsocentral bristles in front of the suture and 

 4 behind. Humerus with long, fine pile. Marginal 

 bristles extraordinarily long, including those of the 

 scutellum. The supraalar bristle and postalar callosity 

 bristle are longer than the antenna. Notopleuron with 

 2 bristles, supraalar with 1, postalar callosity with 2 and 

 scutellum with 2 marginal pairs of bristles. Disc of 

 mesonotum and scutellum with rather abundant, long, 

 fine, erect hairs. Metapleuron with a wide band of 

 long, slender bristles and bristly hairs. Mesopleural 

 pile scanty but long, confined to the posterior border 

 and a few short, dorsal hairs. Both halteres seem 

 broken off, the stalk remaining. Prosternum disso- 

 ciated; metasternum membranous behind. 



Legs : The legs are long and slender, shining, without 

 pollen, with dense, coarse, subappressed pile and with 

 stout and extraordinarily long bristles, especially on the 

 middle tibia and on all the tarsi. Hind femur with a 

 row of long, erect, basal hairs ventrally on the basal 

 half and moderately dense, short, erect pile on most of 

 the ventromedial aspect and ventrolateral^ the pile is 

 downturned. Hind tibia with moderately long but 

 stout, flat appressed bristles, 4 dorsolateral, 3 dorsome- 

 dial, both the basal elements stout and long, and 3 ven- 

 trolateral on the outer half. Middle and anterior fem- 

 ora with conspicuous, ventral fringe of very long, fine, 

 erect pile. Middle tibia with extraordinarily long, 

 stout bristles, 2 anterodorsally at basal and outer third, 

 the second bristle extends to the middle of the long, 

 first tarsal segment, and in addition there are 2 shorter 

 bristles near the base of the tibia. There are 3 short 

 posterodorsal, 3 slightly longer posterior bristles, and 4 

 of the very long, ventral bristles. All these bristles are 

 appressed. Anterior tibia with rather similar bristles, 

 but without apical spine; its posteroventral bristles are 

 longest but a little shorter than those of the middle 

 tibia. Tarsal bristles extraordinarily long, also ap- 

 pressed, and for the most part extending beyond the 

 apex nearly to the end of the next segment. Claws 

 long, sharp and slender, the pulvillus large, long and 

 wide; the long empodium is a little flattened. 



Wings: The wings are large, long and villose. All 

 the posterior cells widely open, the fourth a little nar- 

 rowed, the anal cell open. Alula large, ambient vein 

 complete. Marginal cell widely open, third vein forks 



a little beyond the end of the discal cell. Anterior 

 crossvein enters the discal cell near the outer third. 



Abdomen: The abdomen is long, slender, subcylin- 

 drical with parallel sides, everywhere densely pale pol- 

 linose with long pile on the sides of the first four 

 segments, shorter beyond. The pile is especially long, 

 fine, and dense on the sides of the first two segments 

 and laterally the first segment has 6 long, stout bristles. 

 Lateral metasternum pilose. Terminalia small with 

 the wide, short epandrium convex and notched at the 

 apex. 



Distribution : Neotropical : Graptostylus dolosus, new 

 species. From Chile. 



Graptostylus dolosus, new species 



Densely greyish white, pollinose species, the legs 

 totally shining brownish black, most nearly black on 

 the dorsal surface of the hind femur. Bristles of the 

 head, thorax and abdomen distinctly yellow and even 

 slightly reddish ; those of tibiae and most of the tarsal 

 bristles pale yellow ; some of the tarsal bristles brown- 

 ish black. Length 12 mm. 



Male. Head: The head is black, for the most part 

 completely obscured by pollen, which is thinnest on 

 either side of and behind the ocelli. Proboscis and pal- 

 pus dark reddish brown. Pile of the head nearly white, 

 only the mystax yellow. Antenna black with whitish 

 pollen, which changes to brown on the medial surface 

 of the third segment. 



Thorax: The thorax is densely greyish white pol- 

 linose, with some areas such as the mesopleuron, pos- 

 terior propleuron, and upper sternopleuron faintly 

 brownish yellow pollinose. Mesonotum with a pair of 

 obscure, rather widely separated, brownish black, nar- 

 row, submedial stripes. On each side are 2 rather 

 small, obscure spots of dark brown pollen, one in front 

 of and one behind the suture. Scutellum grey pol- 

 linose. All mesonotal bristles and scutellar bristles dis- 

 tinctly yellow. Metapleural bristles much paler. 



Legs: The legs are black or nearly so with the an- 

 terior tarsus extremely dark reddish brown and some 

 of its bristles the same color and others whitish. Pile 

 of the legs white. 



Wings: The wings are faintly brownish hyaline, the 

 veins light brown. 



Abdomen : The abdomen is densely greyish to almost 

 silvery white pollinose. Bristles of first segment pale 

 yellow; all abdominal pile white. Terminalia brown- 

 ish black with very thin pollen above not obscuring the 

 ground color, none below, its pile and bristles white. 



Type : Male, Valparaiso, Chile, January 25, A. Faz. 

 In the United States National Museum. 



Genus Amphisbetetus Hermann 



Figures 75A, 50S, 990, 999, 1967 



Amphisuetrtits Hermann, Zeitsehr. syst. Hymen, und Dipt., 

 vol. 6, p. 131, 1906. Type of genus : Eabropogon favillaceus 

 Loew, 1S56, by original designation. 



Quite small, short, sparse pilose flies of stout, robust 

 and pollinose appearance. The face is short, receding 



