DASTPOGONIXAE 



ROBBER FLIES OF THE WORLD 



213 



topleural, 1 long stout postsupraalar, and beside it an- 

 teriorly and postmedially several short, slender, bristly 

 hairs. Postalar with only fine, rather short, bristly 

 hairs. Scutelluni with 2 pairs of slender, bristly hairs ; 

 the scutelluni is rather thick and convex; the surface 

 pubescent and apilose. Propleuron with a few, fine, 

 stiff hairs ventrally and a row of similar bristly hairs 

 on the anterior collar dorsally. Mesopleuron pubes- 

 cent only, upper posterior sternopleuron with 5 or 6 

 short, stiff hairs, pteropleuron and hypopleuron apilose ; 

 the hypopleuron has a small patch of long, appressed 

 micropubescence. Metapleuron with a vertical row of 



4 or 5 distinct, moderately long bristles, the lateral meta- 

 notum without pile. Lateral metasternum with 5 or 6 

 long hail's. The ventral metasternum is distinctly chi- 

 tinized in its full length, without pile but micropubes- 

 cent; it is distinctly separated from the long, fully 

 chitinized archlike plate over the postmetacoxal area, 

 also pubescent only. Tegula pubescent only. 



Legs: Anterior and middle femora stout without 

 being swollen; the hind pair is distinctly elongate, 

 spindlelike on the basal third, distinctly though gently 

 dilated apically ; the dorsal pile of all the femora and 

 tibiae is subappressed and setate. The following com- 

 plement of bristles is present: on the hind femur a 

 single, rather long, stout dorsolateral, subapical bris- 

 tle matched by a similar dorsomedial bristle. There 

 are 2 other dorsomedial bristles on the outer half and 

 there is a row of 6 stout, ventrolateral bristles. This 

 tibia is distinctly dilated gradually towards the apex, it 

 is only four-fifths as long as the hind femur and lacks a 

 ventral brush of setae. The hind tibia has the follow- 

 ing bristles : 3 long, strong, dorsomedial bristles, at the 

 base, the middle, and the outer third ; 3 shorter, dorso- 

 lateral and 2 stout ventrolateral on the outer half, 

 besides 3 quite prominent, long, stout, ventromedial 

 bristles. Apex with prominent, long, stout bristles, 1 

 dorsomedial, 1 medial, 3 ventral, 1 ventrolateral, and 

 1 dorsolateral. The middle femur has a prominent, 

 long, anterior bristle near the outer fourth, also a pos- 

 terior, subapical bristle; its tibia has 2 long, slender, 

 anterodorsal, 3 posterodorsal, 3 to 4 posterior, and 2 

 ventral bristles. The first ventral bristle on the basal 

 third is quite long, the second on the distal third is 

 stout. Anterior femur with only short setate pile; 

 its tibia has weak bristles, with 4 posterodorsal, 4 or 



5 posterior and 3 ventral, the element at the basal third 

 is quite long. Apex without spine. Tarsi slender, the 

 anterior basitarsus a little longer than the next 2 seg- 

 ments; all tarsi end in slender, sharp claws chiefly 

 curved at the apex, well developed pulvilli and slender, 

 bristlelike empodium. 



Wings: The marginal cell is widely open, anterior 

 branch of the third vein ends at or just above the wing 

 apex, posterior branch immediately behind the wing 

 apex; the second submarginal cell is rather strongly 

 arched anterobasally, and anterior crossvein situated 

 just beyond the middle of the discal cell. All the pos- 

 terior cells are widely open and not at all narrowed. 

 Anal cell closed with a short stalk; middle end vein 



of the second basal cell very short, or almost absent. 

 Alula linear and narrow; ambient vein ends at the 

 anal cell. 



Abdomen : The abdomen is slender, elongate, a little 

 longer than the wings. The sides of the abdomen are 

 parallel, distinctly more narrow than the mesonotum, 

 subcylindrical, the sides more or less rolled and some- 

 times a little flattened over the middles of the tergites. 

 The second to the fifth segments are distinctly elongate. 

 In the male are eight tergites, the seventh three-fourths 

 as long as the sixth, the eighth is half as long as the 

 seventh. Female with eight tergites, the eighth is three- 

 fourths as long as the seventh. Pile of abdomen mod- 

 erately abundant, subappressed, setate and short with 

 some long, fine pile laterally on the sides of the first, 

 second, and base of the third tergites. First tergite 

 laterally with stiff hairs only. Male terminalia not 

 rotate ; the epandrium is elongate, split to the base into 

 superior forceps. The hypandrium forms a long, 

 medially extended process. Female terminalia with 4 

 or 5 pairs of long, slender, slightly spatulate, spoon- 

 like spines. 



Distribution : Ethiopian : Rhabdogaster maculipennis 

 Engel (1929) ; nudus Loew (1858). 



Genus Psilinus Wulp 



Figures 1105, 1114, 15S7, 1962, 2049 



Psilinus Wulp, Trans. Ent. Soc. London, 1899, p. 85, 1899. Type 

 of genus : Psilinus cinerascens Wulp, 1899, by monotypy. 



Small, slender, dark colored, pollinose flies with 

 greatly reduced pile and bristles and rather short, flat- 

 tened head, which is flattened from the anterior aspect. 

 The general color is rather pale on account of the dense, 

 greyish yellow or pale brown pollen and micropubes- 

 cence. The mesonotum is high, prominent, strongly 

 arched both anteriorly and posteriorly, the femora 

 slender, the hind pair almost as tliick at the base as 

 through the middle and somewhat more elongate than 

 the middle pair. 



Very much like species of Anisopogon Loew and also 

 quite similar to Rhabdogaster Loew; probably related 

 to both. It is of the same size and general appearance 

 as Rhabdogaster and apparently both genera have the 

 postmetacoxal arch chitinized ; I find comparatively few 

 differences between them. The vertex is more deeply 

 excavated, and from a dorsal aspect is rather strongly 

 flared and excavated posteromedially ; the proboscis is 

 more stout, slightly swollen toward the base from the 

 dorsal aspect, a little compressed laterally with a well 

 developed, medial ridge and bluntly rounded apex. 

 The hind femur in Rhabdogaster is distinctly spindle- 

 shaped on the basal half and the vertex is very little 

 excavated. Length 8 or 9 mm. 



I have twice examined from the Hope Collection at 

 Oxford University, England, the specimen of Psilinus 

 cinerascens (type No. 7701) which was believed to be 

 Wulp's type of cinerascens. I failed to note the absence 

 of pulvilli, although I compared this fly critically with 



