446 



"CnsriTED STATES NATIONAL MUSEUM BULLETIN 224 



free space. Female terminalia quite short, 

 cylindroid, of 3 segments. 



Stizolestes, new genus 

 No mane on face or mesonotum 103 



103(102). Superior forceps elongate, comparatively slender, 

 curving apically inward towards medial plane 

 and leaving, from dorsal aspect, a large, free, 

 but elongate, enclosed space. Forceps generaDy 112(109). 



with a tooth-cleft or spur. Female ovipositor 

 of 3 segments and only medium length, laterally 

 and moderately compressed on ultimate 2 

 segments and tenth segment bears 2 or 3 

 characteristic lateral, stout spines; sternites 

 usualh' with bristles .... Philonicus Loew 

 No dorsal curved or oval enclosed space between 

 forceps, or if so, forceps are short, massive, 

 swollen. Females without terminal spines . .104 113(112). 



104(103). Terminalia exceptionally large, wide, generally 

 obtuse. Superior forceps with a deep cleft. 

 Hypandrial plate quite short. Base of second 

 posterior cell strongly swollen anteriorly. End 

 of fourth posterior cell exceptionally convex. 

 Sternites with moderate bristles. Third anten- 

 nal segment with no microsegment. Female 

 terminalia quite short, cylindrical, and conoidal; 

 tenth tergite rather long and directed obliquely 



downward Oligoschema Becker 



Terminalia not exceptionaDy large and swollen. 

 Venation not so constructed 105 



105(104). Style of antenna quite short and stout. Flies 

 with short, rather robust abdomen and densely 

 pilose. Whole scutellar margin and disc excep- 

 tionally densely long, bristly or bristly pilose. 

 Lower occiput with matted, long, fine, dense 

 pile. Sternites and sides of abdomen with 

 unusually long, dense pile. Sternal lappet 



short Trichomachimus Engel 



Flies not of short, robust, densely pilose char- 

 acter 106 



106(105). Males 107 



Females 115 



107(106). Eighth sternite with an apical lobelike or lappet- 

 like extension; dorsocentral bristles before 

 suture weak, short, and inconspicuous . . 108 

 No extension upon eighth sternite 109 



108(107). Scutellar disc with long, bristly hairs. Aedeagus 

 with 5 prongs. Eighth sternite lappet rounded 

 at apex. Sternites with a few bristles. 

 Females characteristic or well differentiated. 



Machimus Loew 

 Eighth sternite lappet excised at apex. Scutellar 

 disc with a few, short, scattered bristles or 

 hairs. Aedeagus with 3 prongs. Sternal pile 

 not bristly. Females characteristic or well 

 differentiated Eutglmus Loew 



109(107). Hypandrial plate exceptionally large and com- 119(117). 



paratively long or extensive 110 



Hypandrial plate quite small or absent . . . 112 



110(109). Anterior portion of mesonotum with a rather 

 dense mane of long, fine acrostical and dorso- 

 central bristles. Face with strongly sloping 

 sides. First and second femur with 2 rows of 120(119). 



ventral, stout bristles. Superior forceps with 

 a deep, extremely narrow cleft. Gonopod 



short Cbatopoda, new genus 



Anterior mesonotum with only fine, rather short 

 pile, or sometimes a few, fine, scattered bristles. 

 Post dorsocentral bristles exceptionally well 121(120). 



developed Ill 



111(110). Face narrow above, divergent below, with steep, 

 lateral margin. Hind femur with a single row 

 of exceptionally long, stout, attenuate bristles. 

 Terminalia exceptionally large, obtuse; superior 



114(113), 



115(106). 



116(115), 



117(115). 



118(117). 



forceps and gonopod (in lateral aspect) tend to 

 be dissociated Thbenia Schiner 



Face with convex, lateral margin. Femora with 

 only fine pile or bristly hairs. Superior forceps 

 attenuate but exceptionaDy stout, apex twisted. 

 Gonopod long, closely associated. Proctiger 

 sagittate apically . . Dinozabbus, new genus 



Mesopleuron on its dorsal border with 3 to 6 

 stout bristles and other bristly hairs. Face 

 gibbosity strongly developed on ventral two- 

 thirds; without ledge. Apex of superior forceps 

 elongate, medially appressed, laterally convex, 

 simple, without notch. 



Acanthopleuea Hermann 



Mesopleural bristles weak and inconspicuous or 

 lacking 113 



Terminalia small; proctiger thrust up at an angle. 

 Eighth tergite very short, especially dorsaUy, 

 often covered. Abdominal segments shortened 

 and abdomen comparatively shortened and 

 somewhat robust; apex of abdomen tends to 

 turn upward. Anterior mesonotal bristles well 

 developed. Tergal and sternal bristles strong. 



DrsMACHUs Loew 



Fhes not so constructed as above. Anterior 

 mesonotal bristles poorly or not at all developed 

 in contrast to the surrounding setae ... 114 



Sternites with strong bristles on at least segments 

 2 to 4 137 



Sternites with fine pile (subgenus of Machinus 

 Loew) ToLMERus Loew 



Tenth tergite (proctiger) of female extremely flat 

 and narrow, wedged into the preceding sec- 

 tion 116 



Tenth tergite (proctiger) of female freely extend- 

 ing beyond the last ventral element of the ovi- 

 positor 117 



Dorsocentral and acrostical bristles long and well 

 developed before suture, reaching to anterior 

 border of mesonotum . . . Dtsmachus Loew 



Dorsocentral and acrostical bristles poorly de- 

 veloped anteriorly with at most only 3 or 4 

 bristles lying before suture . . Eutolmus Loew 



Ovipositor consists of last 2 segments (ninth 

 and tenth) and these segments exceptionally 

 short 118 



Ovipositor consists of 3 or more segments . . 119 



Ovipositor large, the last segment nearly or quite 

 as wide as the preceding segment; - both 

 wider than long; last segment obtusely tri- 

 angular with a shallow, medial groove. 



Antipalus Loew 



Ovipositor small, especially last segment, which 

 forms a smaU, equilateral triangle. 



Thbenia Schiner 



Eighth tergite forms a conspicuous, laterally wide, 

 saddleUke, apically rounded segment to ovi- 

 positor, its margin beset with a fringe of long, 

 stout bristles . . . Cratopoda, new genus 



Eighth tergite without a bristle-fringed, saddle- 

 Uke structure 120 



Dorsal mesopleural border with 3 to 6 stout 

 bristles and bristly hairs. Face gibbosity 

 strongly developed on lower two-thirds but 

 without ledge . . . Acanthopleura Hermann 



Upper margin of mesopleuron with weak pile or 

 very weak, bristly hairs only 121 



Ovipositor of 3 segments of medium length, 

 moderately compressed laterally. Ninth ter- 

 gite elongate and strongly slanted down 

 obUquely Dinozabrcs, new genus 



Ovipositor with ninth tergite not elongate and 

 strongly slanted downward 122 



