262 M. W. R. de V. GRAHAM 



Systasis (Systasis) angustula sp. n. 



$. Bright green to bluish green. Antennae black, scape and pedicellus with green reflec- 

 tions. Legs mainly blackish with a green tinge ; knees and apices of tibiae, also an external 

 stripe on the fore tibia, testaceous ; fore tarsi brownish, mid and hind tarsi pale testaceous 

 becoming brownish distally, their fifth segment fuscous. Tegulae black with a metallic tinge ; 

 wings hyaline, venation brownish testaceous. Length i -8 to 2 mm. 



Lower face, on either side of clypeus, rather irregularly reticulate and with several con- 

 spicuous piliferous punctures. Head in dorsal view 2-1 to 2-2 times as broad as long ; temples 

 about one quarter as long as eyes. Head in frontal view about 1-25 times as broad as high, 

 with vertex not strongly arched. Eyes separated, on vertex, by 1-25 to 1-3 times their length. 

 Antenna with scape reaching about to level of lower edge of median ocellus, its length slightly 

 less than the transverse diameter of an eye ; combined length of pedicellus and flagellum about 

 equal to breadth of head ; pedicellus (profile) nearly twice as long as broad, approximately 

 as long as anelli plus first funicular segment ; flagellum slightly clavate, proximally slightly 

 stouter than the pedicellus (in profile) ; funicular segments increasing very slightly in length, 

 the fifth as long as the first segment of the clava ; the segments are quadrate, or the fourth and 

 fifth very slightly transverse ; clava about as long as the three preceding funicular segments 

 together ; sensilla sparse ; hairs of flagellum subdecumbent. 



Thorax squat, 1-3 to 1-4 times as long as broad. Fore wing much as in parvula (cf. Text-fig. 

 196) ; basal vein bare or with one or two hairs ; speculum broad and continued, on upper 

 surface of wing, as a bare strip below the marginal vein as far as the stigmal vein ; the triangular 

 area between the postmarginal and stigmal veins is mainly bare, and there is a small bare spot 

 below the stigma ; disc of wing, beyond the speculum, rather sparsely haired ; postmarginal 

 vein 1-2 to 1-3 times as long as the stigmal vein. Spur of mid tibia about three quarters the 

 length of the first tarsal segment. 



Gaster long-ovate, as long as head plus thorax, slightly narrower than the thorax, 2 to 2-3 

 times as long as broad, acutely pointed apically. 



o*. Differs from $ chiefly in the antennae, gaster, and smaller size (1 -5 to 1 -6 mm.). Antenna 

 with scape broader, only slightly more than three times as long as broad, with a row of small pits 

 along its front edge ; combined length of pedicellus and flagellum slightly greater than breadth 

 of head ; pedicellus slightly shorter than in $ ; funicle proximally as stout as the pedicellus 

 when the latter is seen in dorsal view, hardly thickening distad ; its segments quadrate, or the 

 proximal ones very slightly longer than broad ; clava nearly as long as the three preceding 

 funicular segments together ; hairs of flagellum subdecumbent. Postmarginal vein only 

 slightly longer than the stigmal vein. Gaster oval, depressed ; hardly as long as, and slightly 

 narrower than, the thorax. 



This species is very close to parvula Thomson and differs only in the characters 

 mentioned in my key. The $ is also very near that of longula Boucek, but differs 

 particularly in its relatively shorter gaster, also in some smaller details, as follows : 

 eyes rather larger, separated (on vertex) by 1-25-1 -3 times their length (by about 

 1-45 times in longula) ; head in frontal view distinctly transverse, with vertex less 

 strongly arched (in longula more subcircular, with vertex strongly arched) ; in dorsal 

 view the head is rather more transverse (in longula hardly twice as broad as long), 

 with the temples shorter (more than one third as long as eyes in longula) . 



Holotype $. England : Surrey, Riddlesdown, from Kiefferia pimpinellae Hed. 

 (Dipt., Cecidomyiidae), 20.ix.1947 (M. Niblett), in Hope Department, University 

 Museum, Oxford. 



Paratypes. Same data as holotype, 3 g, 3 $ ; Surrey, Effingham Common, from 



