I.APHIUINAH 



ROBBER FLIES OF THE WORLD 



371 



Antenna long and slender. Fourth posterior cell as long or 

 even shorter than the discal cell. Spine of third antennal 

 segment near the middle. Face narrow and sometimes ex- 

 ceptionally reduced in width, but vertex divergent ... 25 



25. Apex of third antennal segment with a microsegment. Mi- 



crosegment short or long and microsetate as normal, or 

 densely short plumose or with long pubescence .... 26 

 No microsegment present. Third antennal segment obtuse 

 or bluntly pointed, without special or exceptional pile and 

 with or without apical spine 35 



26. A distinct, conspicuous spine present at apex of the third 



segment above the microsegment, or more rarely borne 

 on the base of the microsegment ; rarely reduced to a 

 short, blunt spine immediately before the microseg- 

 ment 27 



No obvious spine present at the end of the third segment 

 or on base of the microsegment 34 



27. Four posterior cells only Chtmedax Hull 



Five posterior cells present 28 



28. The spine is clearly attached to the base of the microseg- 



ment. Third antennal segment falcate, long and slender, 

 arched, the base wide, the ventral surface from base to 

 apex with drooping membrane. Microsegment rather long 

 but obtusely rounded, the basal spine conspicuous. Abdo- 

 men with parallel sides and with fine, scattered punctures 

 and tergal bristles. Face quite narrow ; vertex divergent ; 

 occipital bristles spinous. Scutellar bristles exceptionally 



long and stout Catonomtia, new genus 



The spine, sometimes minute, sometimes long, is attached 

 clearly to the end of the third antennal segment ... 29 



29. Ventral surface of hind femur with distinct spines and 



spinous bristles 30 



Ventral surface of hind femur with at most some slender 

 bristles and bristly hairs 31 



30. The microsegment at end of third antennal segment is cup- 



like, with enclosed spines. Abdomen comparatively broad 

 and somewhat flattened, or long oval, at most finely punc- 

 tate. Hind femur a little swollen, the ventral spines 

 with tubercles .... Rhathimomyia Lynch Arribalzaga 

 The microsegment at the end of the third antennal segment 

 consists of a virtually bare, short, fleshy style with a 

 spine at its base. Hind femur with distinct, conspicuous, 

 stout, sharp, tuberculate, spinous bristles. Abdomen not 

 long and oval; spines beneath hind femur arise from 

 tubercles Dissmeeyngodes Hermann 



31. Male face with golden scales of pile and first antennal seg- 



ment scarcely longer than the second. Female face with 

 a few, long, slender bristles. Abdomen with punctures 

 and 7 tergites; mesonotuni smooth. First antennal seg- 

 ment a little longer than second segment; no tergal 



bristles Despotiscxjs Bezzi 



Face not dimorphic. Face pile consists of hairs and bristles. 

 If scales are present rarely, they are present in both sexes 

 and the first antennal segment is about twice as long 

 as the second 32 



32. The microsegment is flat, comparatively short and blunt 



at apex. Third segment microsegment attached usually 

 with a downward angle and a distinct characteristic spine 

 emitted from the end of the third segment above the base 

 of the microsegment. The base of the third segment is 

 bent and attenuate; first segment without conspicuous 

 bristle; occiput without strong bristles but tumid and 

 strongly developed everywhere except at vertex. Face 

 nearly plane, narrowly visible to the antenna. Abdominal 



pile usually flat appressed Atoniomyia Hermann 



The microsegment is long, the apex either blunt or 

 finely attenuate 33 



33. Third segment microsegment half as long as the third seg- 



ment or longer, and densely long pubescent, a spine at apex 

 of the third segment; proboscis very small, quite blunt, 



cylindrical and no longer than the face; antenna ex- 

 ceptionally long and slender . Diciiaetothyrea de Meijere 

 Third segment microsegment narrow and attenuate, rather 

 sharply pointed; antenna scarcely longer than the face, 

 the supraoral bristles quite stout, the upper occiput 

 with 4 spikelike spines; proboscis very short but 

 quite stout Opeatoceeus Hermann 



34. Face with scales and slender bristles. No obvious spine 



present at end of third antennal segment, although a 

 minute bristle may be present or absent. Face in profile 

 evident only below and not prominent. 



Goneccalypsis Hermann 

 Face without scales. Third segment microsegment held 

 nearly straight; occiput almost absent in profile, with 6 

 or more stout bristles; first antennal segment bristles are 

 long and stout; face prominent only below and there 

 produced Lowineixa Hermann 



35. Face and front with parallel sides, the vertex not wide and 



not flared posteriorly. Face plane and antenna set on a 

 slightly produced front. Occiput well developed in the 

 middle and below, with stout bristles. Antenna quite long 

 and slender, with parallel sides ; third segment especially 

 long and first segment 4 or 5 times as long as second seg- 

 ment. Thorax and abdomen coarsely punctate. Apex 

 of third antennal segment with a short spine, well hidden 

 in a deep and dense but rather short, stiff pile. Seutellum 

 with only short, bristly hairs . . . Batheopsis Hermann 

 Face divergent above and front and vertex still wider ; the 

 postvertex strongly excavated and flared 36 



36. Antenna exceptionally long and slender, the first and third 



segments especially elongate 37 



Antenna not of exceptional length and usually almost as long 

 as the head or a little longer 33 



37. Grossly punctate flies, bare with pile reduced to microscopic, 



scattered setae. Occiput bare except for 4 stout, laterally 

 placed spines or spinous bristles. Mesonotum developed 

 anteriorly into a strong hump . . Cyphotomyia Williston 

 Without exceptionally deep or conspicuous surface puncta- 

 tion; pile abundant, scattered, long and fine; occipital 

 bristles weak or absent altogether . . Ceeotainia Schiner 



38. Fourth posterior cell longer than the discal cell ; face totally 



plane with eye, above and below; proboscis longer than 

 face, bluntly pointed, comparatively slender; fourth pos- 

 terior cell stalk short. Third antennal segment rather 

 stout, nearly twice as long as the combined length of the 

 first 2 segments and the apex bluntly pointed. 



Oidabdis Hermann 



Fourth posterior cell shorter or of the same length as discal 



cell 39 



39. Third antennal segment with a large, oblique, apical pit 



which contains a short, stout spine. Face short, plane 

 near the antenna, but the face is wide and the front is 

 slightly divergent to the vertex. Proboscis obtuse, no 

 longer than face ; eye posteroventrally recessive, the occi- 

 put correspondingly thick Automolina Hermann 



Third antennal segment simple at apex. The anterior branch 

 of the third vein ends above the wing apex. A dorsal 

 apical spine on the third antennal segment is present 

 or absent 40 



40. End veins of discal and fourth posterior cells nearly aligned, 



the cells of nearly equal length. Front, face and occiput 

 with exceptionally abundant, long, stiff, bristly pile. Dor- 

 sal subapex of third antennal segment with a distinct 



spine Lampbozona Loew 



Fourth posterior cell much shorter than the discal cell. 

 Face with only 2 or 3 long, bristly hairs above and a like 

 number on the oral margin. Apex of third antennal seg- 

 ment without a segregated, dorsal spine. Often pale 

 colored flies (Laphbiini) .... Cenochbomyia Hermann 



