A8ILINAB 



ROBBER FLIES OF THE WORLD 



443 



55(54). First posterior cell greatly narrowed before the 

 apex. Medial crossvein or lower end vein of 

 discal cell exceptionally lengthened, so that 

 discal cell appears to be closed by one vein . . 56 



Venation of wing not so constructed 57 



56(55). Abdomen greatly flattened, broad, with con- 

 spicuous lateral tufts of hairs. Female eighth 

 segment cylindrical, longer than wide. Very 



large flies Blepharotes Westwood 



Abdomen cylindrical and distinctly tapered; 

 marked hair tufts absent. Ovipositor strongly 

 compressed laterally . . . Pakaratus Ricardo 

 57(55). Dorsal occipital bristles proclinate; eye greatly 

 narrowed ventrally. Scutellum with a pair of 

 strong marginal bristles ; pilose. Male termina- 

 lia small. Medial bristles present on whole 

 length of thorax but scanty; discal cell not 



narrowed at apex Regasilus Curran 



Occipital bristles slightly curved. Apex of discal 

 cell greatly narrowed. Gibbosity strong, occu- 

 pying lower three-fourths of face. 



Myaptex, new genus 

 58(54). Face nearly plane, narrowly visible dorsally from 

 lateral aspect, total ventral elevation quite 

 short. Second submarginal cell basaUy 

 widened both anteriorly and posteriorly. 

 Antennal style as long as third segment. 

 Ovipositor composed of 4 segments, all strongly 

 compressed laterally; eighth segment twace aa 

 long as seventh; all 4 segments progressively 

 and strongly reduced in height from ventral 

 surface; dorsal surface plane. Small flies. 



Leptoharpacticds Lynch ArribdJzaga 

 Face with a moderate but obtusely conical or 

 triangular elevation ventrally. Second mar- 

 ginal cell widened only anteriorly. Flies of 



medium size 59 



59(58). Face in middle seventh of head width, wider 

 below. No stout, lateral, occipital bristles. 

 Second marginal cell quite narrow basaUy and 

 posterior branch of third vein curved forward. 

 Face without pile. Bristles restricted to 1 row. 

 The 3 segments of ovipositor all relatively 

 short and last 2 quite small and moderately 

 compressed laterally . . Leinendera Carrera 

 Face in the middle fifth to fourth of head width, 

 or if more narrow, the face bears numerous 



bristles 60 



60(59). End of fourth posterior cell plane. Face with 

 numerous bristles and bristly hairs, these 

 restricted to ventral half. Ovipositor with a 

 pair of submedial, terminal spines. 



Neocerdistus Hardy 

 End of fourth posterior cell convex. Ovipositor 



without spines 61 



61(60). Face with few bristles or hairs and face about a 

 fourth head width. Posterior branch of third 

 vein is continued in same plane as stem of third 



vein Ntssoprosopa, new genus 



Face with numerous bristles, width usually less 

 than a fourth to as little as a sixth head width. 

 Posterior branch of third vein not continued in 

 same plane as stem of third vein. 



Cerdistus Loew 

 62(53). First posterior cell closed and stalked. 



Megadrillus Bigot 



First posterior cell open 63 



63(62). Males 64 



Females 71 



64(63). Distal half of wings anteriorly expanded in con- 

 trast to basal half. Discal cell usually very 

 strongly occluded by fourth posterior cell. 

 Occipital bristles very strongly proclinate. 



Mesonotum never with mane. Medial cross- 

 vein or lower end vein of discal cell as short or 

 shorter than upper end vein (anterior inter- 

 calary vein) . Anterior crossvein rectangular . 65 

 Wings not expanded in contrast to plane of basal 

 half of costa; medial crossvein or lower end 

 vein of discal cell longer, and often much 



longer, than upper end vein 67 



65(64). Face nearly or quite plane, with a few hairs or 

 bristles on dorsal half. Wings quite gently 

 expanded; anterior crossvein enters discal 



cell at outer fourth Stnolcus Loew 



Face distinctly convex, with usually numerous, 

 long bristles throughout, confined chiefly to 



middle 66 



66(65). Wing very gently and slightly expanded. Discal 

 cell only slightly occluded. Base of second 

 posterior cell very little wider than end of 

 discal cell. Costal vein scarcely or not at all 



expanded Hobbtus Bromley 



Wing strongly expanded. Discal cell strongly 

 occluded. Base of second posterior cell dis- 

 tinctly wider than end of discal cell. Costa 

 thick and swollen .... Dasophrys Loew 

 67(64). Dorsal occipital bristles stout, not proclinate. 

 Dorsal bristles of face few and scattered. Ter- 

 gal bristles present . . . Dysclytds Loew 

 Dorsal occipital bristles distinctly and strongly 

 proclinate. Face usually with numerous, long 



hairs or bristly pile 68 



68(67). Tergites without discal bristles; scutellum with a 

 double row of long, upwardly turned and 

 directed, curved marginal bristles. Male 



terminalia long or globose 69 



Tergites with distinct discal bristles. The anterior 

 crossvein rectangular or obUque. End vein of 

 fourth posterior cell not at all aligned with 



lower discal end vein 70 



69(68). End vein of fourth posterior cell nearly or quite 

 aUgned with lower end vein of discal cell. 

 Anterior crossvein strongly obhque. 



Neolophonotus Engel 

 End vein of fourth posterior cell not at aU aligned. 

 Anterior crossvein nearly rectangular. 



Neodasophrys Ricardo 

 70(68). Only tergites with bristles. Anterior crossvein 

 usually very strongly oblique. 



LoPHOPELTis Engel 

 Tergites and sternites each with prominent 



bristles Lophybus Engel 



71(63). Ovipositor exceptionally long and xiphoid . . 72 



Ovipositor short, differently constructed . . 75 



72(71). Dorsal occipital bristles strongly proclinate. 



Lower end vein of discal cell usually as short or 



shorter than upper section 73 



Occipital bristles stout but not procUnate. Scutel- 

 lum with 2 marginal bristles. Tergites with 



discal bristles Dysclytus Loew 



73(72). Face nearly or quite plane, with few hairs or 

 bristles on the dorsal half. Anterior crossvein 

 enters discal cell at outer fourth. Discal cell 



strongly occluded Synolcus Loew 



Face stongly convex anteriorly. Scutellum with 

 2 to 6 marginal bristles. Tergal bristles present 

 or absent. Anterior crossvein enters discal cell 



near or before the middle 74 



74(73). Scutellum with 2 to 4 marginal bristles. Weak 

 tergal bristles present. Sternites with bristle- 

 like hairs. Base of second posterior ceU scarcely 



swollen HoBBYUS Bromley 



Scutellum with 4 to 6 marginal bristles. Tergal 

 bristles usuaUy absent. Base of second posterior 

 cell moderately swollen . . . Dasophrys Loew 



