750 



ASILTD^ 



Fig. 403. — Leptogaster cylindrica S ■ x 14. 



terminal style wliich is half as long as the third antennal joint and may bear a 

 minute hair -like terminal bristle. 



Thorax (fig. 403) somewhat globular and almost bare, there being only two strong 



bristles present of which one is praesutural and 

 the other supra-alar though the latter one is 

 placed so far out on the disc as to appear to 

 be intra-alar; some minute easily overlooked 

 bristles however occur which indicate other 

 Asilid bristles, as sometimes a thin one exists 

 on the postalar calli and two rows of very 

 minute dorso-central bristles can be traced after 

 the suture, while some minute pale hairs occur 

 near the praesutural bristle; pleurae covered 

 with dense tomentum which develops into fine 

 short pubescence on the front part of the 

 mesopleur^ and on the upper front corner of 

 the sternopleuree ; metapleurse with very faint 

 minute hairs which indicate the usual tuft or 

 fan. Scutellum small, bearing minute marginal 

 pubescence ; metanotum small, concealed beneath the scutellum. 



Abdomen very long and thin, rather dangling downwards, slightly widened at 

 the end in the male, bearing very minute pubescence but witli a ciliation (almost 

 bristly) along the sides of the hindmargin of the basal segment ; basal segment short, 

 second very long and with the spiracular dots far fi'om the base (about one-third 

 down the segment), next five segments long, but the eighth segment very short. 

 Genitalia of the male rather knobbed and complex, those of the female truncate 

 or at any rate short. 



Legs long and thin (especially the hind pair), the hind femora distinctly, 

 and the hind tibiae somewhat, clavate ; the 

 legs are almost unarmed, but the the femora 

 have some subapical bristles, the anterior 

 tibias have about four postero-ventral incon- 

 spicuous bristly hairs, the hind tibiae have 

 three or four irregular inconspicuous bristles 

 about the middle, and all the tibiae have 

 long thin spurs ; tarsi with strong bristles 

 about the tip of each of the four basal 

 joints and with numerous plantar bristles. Pulvilli absent, but the claws remark- 

 ably long and gently curved, with the empodium showing between them as a strong 

 sharp bristle (fig. 404). 



Wings small, much shorter than the abdomen • marginal cell wide open ; cubital 

 fork long and rather narrow ; second posterior cell unusually long as it commences 

 in a point considerably before the end of the discal cell, and in consequence the 

 upper margin of the discal cell is divided into three (often nearly equal) spaces ; all 

 five posterior cells widely open ; anal cell long and rather narrow, almost parallel- 

 sided but slightly narrowest soon after tiie postical fork so that it ends rather widely 

 open ; discal cell emitting the usual three simple veinlets (fig. 406), or apparently 

 four (fig. 405) when the small cross-vein is absent ; hind angle of the wing com- 

 pletely sloped aAvay, and the alulae practically absent, though the wings have a 

 long fringe where the latter should be ; wing-membrane slightly rippled all over. 

 Alar squamae small and without fringes ; thoracal pair practically absent. Halteres 

 with an unusually long stem. 



This genus is easily distinguished from any other Palrearctic one by 

 the elongate slender form combined with the remarkably long claws and 

 abortive pulvilli. 



Leptogaster is a genus of about seventy species from all parts of the 

 world except perhaps New Zealand, and of these about sixteen occur in 

 Europe; the distinctive characters of some of the species are not well 

 defined. According to specimens in Bigot's collection L. fuscipennis Gay 

 from Chili has nothing to do with the genus, as they have the pulvilli 



Fig. 404.- 



-Leptogaster cylindrica (J. 

 front tarsus.) x 45. 



(Right 



