442 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



very large flies with elongate, tapered ab- 

 domen Pboctacanthus Macquart 



Face very stongly produced, with a deep, hori- 

 zontal ledge above gibbosity 35 



35(34). First posterior cell greatly narrowed in middle by 

 expansion of both the cell before and cell be- 

 hind; costa and marginal cell strongly ex- 

 panded. Eighth sternite greatly produced; 

 bilobate, with on each side a dense, apposed 

 brush. Gap sometimes found between superior 

 forceps and gonopod. Female ovipositor con- 

 sists of a long, cylindrical, slightly tapered 

 structure composed of segments 7 to 10, 

 inclusive; segment 8 the longest; ninth tergite 

 with an acute, elongate extension, extending 

 beyond proctiger . . Lochmorhynchds Engel 

 First posterior cell not unusually narrowed . 36 

 36(35). Ventral plate (hypandrium) absent, gonopod often 

 with a dense, apposed brush of pile; forceps 



elongate Nerax, new genus 



Ventral plate (hypandrium) present, even if 



short 37 



37(36). Abdomen robust at base, comparatively short, 

 strongly tapered; terminalia large, elongate, 

 the superior forceps with deep, lateral cleft. 



Cratolestes, new genus 

 Abdomen never exceptionally stout and tapered; 

 male terminaUa without long, dorsal and ven- 

 tral prongs 38 



38(37). Ventral process bearing a conspicuous basketlike 



apparatus of many long and curved, crowded 



bristles .... Lonchodogonds, new genus 



Ventral process strongly constricted before apex, 



with a few loosely scattered, fine, short bristles. 



Philonerax Bromley 



39(32). Apex of abdomen with spines 40 



Apex of abdomen without spines 41 



40(39). Tenth tergite divided, bearing short spines. 



Proctacanthus Macquart 



Female terminalia bears a wide, extensive band 



of heavy, short spines. Face with dense, long 



pile except above gibbosity; lower occiput 



similarly pilose .... Eccritosia Schiner 



41(39). Female terminalia exceptionally, greatly flattened. 



Nerax, new genus 

 Female terminalia never greatly compressed 



lateraUy 42 



42(41). Ninth and tenth tergites expanded into a short, 

 wide, bulbhke or clublike structure. 



LoNCHODOGONUs, new genus 

 Ninth and tenth tergites subcylindrical, long or 



short 43 



43(42). Distal 2 tergites very short, depressed downward 

 at apex. Eighth segment excluded. 



Philonerax Bromley 

 Distal 2 tergites not exceptionally shortened. 

 Ovipositor cylindrical. Eighth segment in- 

 cluded LOCHMORHYNCHUS Engel 



44(26). Slopes of lateral metanotal callosity with bristly 



pile 78 



Slopes of lateral metanotal callosity with pollen 



or mieropubescence only 45 



45(44). Rim of scutellum not impressed; scutellum high, 



thick and convex 46 



Rim of scutellum with a distinct, impressed 



crease 47 



46(45). Eighth sternite produced into a long, spadehke 

 process, extending nearly as far as the long 

 gonopod, and with tuft of bristles at apex; 

 hypandrium shorter and enclosed between. 

 Hind femur with close-set group of 15 short 

 setae ventrally near apex. Female unknown. 

 Catostola, new genus 



Eighth sternite short, not strongly produced; 

 gonopod short or long. No such tuft of femoral 

 setae present 136 



47(45). Face extremely narrow in middle eighth of head 



width or less 48 



Face of moderate width, usually a fourth to a 

 third head width, rarely as little as a fifth of 

 head width 51 



48(47). Second submarginal cell quite long and narrow 

 at base widened only anteriorly. Third an- 

 tennal segment moderately long. Arista also 

 moderately long. Face high, almost plane, 

 a mere suggested gibbosity situated above 

 epistoma. Palpus slender, cylindrical. Male 

 terminalia elongate; dorsoventral, distally en- 

 larged, superior forceps narrowed at the base. 

 Female ovipositor extremely long and narrow, 

 composed of 6 segments, the fifth to seventh 

 compressed laterally, the eighth to tenth sub- 

 cylindrical Lycoprosopa, new genus 



Second submarginal cell not remarkably long and 

 narrow; male superior forceps broadly joined 

 to preceding segment; female ovipositor not 

 composed of 6 segments 49 



49(48). Third antennal segment short, arista long. Face 

 with a very few long bristles dorsally. 



Senoprosopis Macquart 



Third antennal segment exceptionally long, arista 



short 50 



50(49). Third antennal segment extremely long, of nearly 

 uniform width, bearing at the apex an excep- 

 tionally short style . . Glaphyropyga Schiner 

 Third antennal segment quite elongate but atten- 

 uate. Style longer, with or without a preceding 

 microsegment. Scutellar rim impressed; lateral 

 metanotum without pile . . . Opopotes Hull 



51(47). Middle femur and tibia with spinous bristles. 

 Stout, rather robust flies. Style of the slender, 

 much elongate third segment quite short and 

 fleshy. End vein of fourth posterior cell and 

 medial crossvein at end of discal cell nearly 

 aligned. Discal cell posteriorly strongly oc- 

 cluded. Face poorly developed. Ovipositor 

 conical-cylindrical. Tergal bristles beyond 

 segment one absent . . . Polyphonius Loew 

 Middle femur and tibia with only normal bristles. 



52 



52(51). Face very short, both above and below, following 

 curve of eyes and bearing an exceptionally 

 dense, medial face mane or vertical brush of 

 long, fine pile. Third antennal segment long, 

 attenuate, with long, basal microsegment and 

 longer, fine style. Eye posteriorly plane, reces- 

 sive below. Male wing expanded. Mesonotum 



with a mane Hippomachus Engel 



Face much longer and with distinct gibbosity, at 

 least below. Face mane rarely present; 

 mesonotal mane rarely present 53 



53(52). Facial gibbosity general, beginning at or immedi- 

 ately below antenna and leaving face distinctly 

 and gradually convex over whole height. Face 

 both above and below with abundant, very 



long pile or bristles 62 



Face with a distinct convex gibbosity on lower 

 half or two-thirds of face, or quite level with 

 eyes on upper half and nearly or quite plane in 

 profile, with a small, produced triangle ven- 

 trally 54 



54(53). Ventral face gibbosity sti'ong, with numerous 



bristles, the lower elements stouter .... 55 



Face gibbosity weak, confined to lower half of 



face or less, with usually a single row of lower 



marginal, stout bristles 58 



