214 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



PART 1 



a specimen of Rhabdogaster nudus and at that time I 

 could see no difference between the two, except that 

 RhaMogaster definitely has the postmetacoxal area 

 forming a chitinized arch, as in Atomosia Macquart of 

 the Laphriinae. It appeared to me that the postmeta- 

 coxal region of this Hope Museum specimen of Psilinus 

 cinerascens also had the postmetacoxal area chitinized, 

 but because of the position of the pin and the condition 

 of the specimen I could not make certain of this point. 

 If it is chitinized and pulvilli are present, it will fall 

 in the genus Rhahdogaster; if not chitinized and pulvilli 

 are present it will go to Anisopogon; if pulvilli are 

 absent, as Wulp stated in his description, it is a valid 

 genus, related to both Anisopogon and Rhahdogaster. 

 While my redescription of Psilinus cinerescens affirms 

 the presence of pulvilli, and Wulp's description is based 

 on their absence, further material is needed and more 

 study, as the above specimen was in a very poor state 

 of preservation, and I may be mistaken in assuming it 

 to be Wulp's type. Wulp compared his specimen with 

 Rhadinus Loew and Leptogaster Meigen, both of which 

 lack pulvilli, and it does not seem likely that he was 

 mistaken about the absence of pulvilli. 



Head, lateral aspect: Face extremely short, plane 

 with the eyes and for the most of its length barely visible 

 near the epistoma, this portion rounded and retreating. 

 Epistoma small, moderately oblique, concave and bare. 

 Occiput with a fringe of stiff, yellowish, bristly hairs 

 dorsally and along the middle. These hairs are placed 

 rather considerably back from the eye margin. Ventral 

 pile delicate, longer and also yellowish white. The eye 

 is plane posteriorly through the middle, rather strongly 

 recessive below on the lower third. Proboscis slightly 

 compressed toward the apex but rather short and ex- 

 tended slightly downward and chiefly forward beyond 

 the face but not quite to the end of the mystax. Palpus 

 comparatively large, clearly of two segments, with the 

 first segment excavated, the second segment considerably 

 longer than the first and placed at an angle with 

 rounded, closed, blunt apex, which bears long, yellow 

 hairs laterally and ventrally, but none at apex. An- 

 tenna attached a little above the middle of the head. 

 Third segment now missing. 



Head, anterior aspect: Face grej'ish white micro- 

 pubescent or pollinose with a number of scattered, rather 

 long, very slender bristles or bristly hairs, which are 

 pale yellow and confined to the lower half of the face. 

 Remainder of face without pile. Front coarsely pubes- 

 cent, greyish white, without pile or bristles. Ocel- 

 larium large, rather high with vertical sides, the an- 

 terior ocellus considerably enlarged and convex, the 

 whole without pile, although placed deeply on the pos- 

 terior slope there are 2 or 3 short hairs. Anterior eye 

 facets rather strongly enlarged over the medial half. 



Thorax : Mesonotum rather high and strongly convex 

 and almost as convex posteriorly. It is densely ap- 

 pressed, greyish to brownish yellow micropubescent or 

 pollinose. There is a single row of 5 or 6 very fine, 

 short, scanty, acrostical hairs separated by a rather wide, 

 micropubescent space and 1 row of fine, scattered, 



dorsocentral, bristly hairs anteriorly; the pale dorso- 

 central bristles remain extremely fine but become con- 

 siderly longer behind the suture; on the sides of the 

 mesonotum there are 2 notopleural bristles. There are 

 at most 2 or 3 very weak, bristly hairs on the supraalar 

 region. Postalar callosity with only short pile. Scutel- 

 lum with at least several pairs of very slender, mod- 

 erately long, upturned, stiff, yellow, bristly hairs; the 

 scutellum is yellow pollinose, without pile, Pronotum 

 with stiff or bristly hairs ; there is a little, very delicate 

 pile on the lateral pronotum and the propleuron. 

 Metanotal slopes bulbous, micropubescent only ; hypo- 

 pleuron with high micropubescence only ; metapleuron 

 with 6 or 8 long, slender, yellow, bristly hairs. There 

 are 2 or 3 hairs on the upper posterior sternopleuron ; 

 mesopleuron with 2 or 3 weak hairs; pteropleuron 

 without pile. Pleuron brownish black and densely pale 

 yellowish brown pollinose. Lateral metasternum with 

 7 or 8 fine, long hairs; ventral metasternum similarly 

 pilose; postmetacoxal area with a long, completely 

 chitinized arch. 



Legs: The legs are slender; the hind femur is short, 

 appressed pilose; it has a pair of dorsoapical, bristly 

 hairs. There is a row of fine, long, pale, stiff, bristly 

 hairs ventrolaterally and a still longer row of 8 or 9 

 bristly hairs ventromedially, and additional, shorter, 

 erect pile. Dorsal pile appressed. Tibia with weak 

 pile on the distal half and with 2 dorsal, 2 ventral, 



1 lateral, and 2 or 3 medial bristly hairs. Apex with 



2 dorsal, 1 lateral, and 1 or 2 medial, pale bristles. 

 There are 2 or 3 black, ventral, bristly hairs. Middle 

 femur with long, fine pile beneath and with 1 weak, 

 subapical anterodorsal, bristly hair, also with several, 

 weak, long, yellowish bristles ventrally. Middle tibia 

 with 3 moderately strong, long, anterior bristles, 4 pos- 

 terior bristles, and 3 or 4 ventral bristles. Anterior 

 femur without bristles. Anterior tibia with 3 short 

 dorsal and 4 long, slender, posterior bristles ; apex with- 

 out spine. Claws slightly curved and sharp; pulvilli 

 three- fourths as long as claws; empodium long and 

 slender. 



Wings : All posterior cells widely open. The ambient 

 vein ends sharply at the end of the fourth posterior cell. 



Abdomen: The abdomen is slender, with nearly 

 parallel sides, subcylindrical, slightly flattened in the 

 middles of the first five tergites; first tergite about a 

 fourth as long as the second. Abdomen densely 

 brownish ochraceus pollinose, with short, scanty, sub- 

 erect, reddish pile. Sides of first tergite with a few, 

 long, stiff, pale hairs. There are eight well developed 

 tergites. Ovipositor with 5 pairs of rather sharp, red- 

 dish brown spines laterally and paired, flaplike lobes 

 below held together in a V-shaped position. 



Distribution : Ethiopian : Psilinus cineraseens Wulp 

 (1899). From Aden. 



I quote Wulp's description : 



Belongs to the Dasypogoninae without terminal spur to the 

 front tibiae and without pulvilli. 



Small, slender, not hairy. Front very slightly excavated; 

 ocelli distinct; face flattened, narrower than the eyes, with 



