NO. 120C. ICHNE VMOy FLIES— A SHMEA D. 71 



16. Abdominal segments 2 and 3 wider than long; transverse median nervure in 



hind wings broken below the middle. 

 Transverse median nervure in front wings not interstitial, uniting witli the 

 median vein beiiind the basal nervure; male antennae tiol dilated 



beyond the middle (498) Ttemalopi/gun Holmgren. 



Transverse median nervure in front wings interstitial with the basal nerv- 

 ure; male antennae dilated beyond the middle. 



(499) Baryceros Gravenhorst. 

 Abdominal segments 2 and 3 not distinctly wider than long; transverse median 

 nervure in hind wings broken exactly at the middle. 



(500) Si/nag)-yp)niji F(')rster. 



17. Clypeus not separated at base 18 



Clypeus separated at l)ase. 



Mesonotum wilh distinct furrows anteriorly; longer spur of hind tibia' not 

 half as long as the basal joint of tarsi (501) Iloniobia, Forster. 



Mesonotum without furrows anteriorly; longer spur of hind tibiae longer 

 than half the length of basal joint of tarsi. 



(502) Zemiophora Fitrster. 



18. First abdominal segment tritli sharp carinas extending from the spiracles to the 



apex (503) Synonefes Forster. 



First abdominal segment uithout such carinae. 



(504) Amorphognathon F()rster. 



19. Clypeus not transversely divided by an elevated line or ridge 26 



Clypeus transversely divided by an elevated line or ridge, the anterior part 



somewhat abrupt or impressed, and also usually differently colored 



from the basal part. 



Frons above the antennse witJi, a strong tubercle 20 



Frons above the antennae normal, or without a tubercle 21 



20. Frontal tubercle incised above; lateral clypeal foveae clothed with long hairs. 



(505) Odoconus Forster. 



Frontal tubercle not incised above; lateral clypeal fovese not clothed with long 



hairs (506) Cosmoroims Forster. 



21 . Metanotum more or less completely areolated 22 



Metanotum exareolate, entirely smooth. 



Metanotum without longitudinal carinse but %mth a strongly elevated trans- 

 verse carinse {507)Psilos(irge Forster. 



Metanotum with longitudinal carinse but without an elevated transverse 

 carina (508) Qu<idrig<in(i Davis. 



22. Antennal fovea urith an elevated margin 23 



Antennal f(jvea ^vithout an elevated margin 24 



23. Antennal fovea with an elevated margin above (509) Otitochilus Forster. 



Antennal fovea with an elevated margin within (510) Synih(>?thn.<i Forster 



24. Clypeus normal without teeth anteriorly 25 



Clypeus with two median teeth anteriorly (511 ) Neleges Forster. 



25. Mandibles with the teeth of an equal length (512) Tryphon Gravenhorst. 



Mandibles with the teeth of an unequal length (513) Polyrhysia Fdrster. 



26. Transverse median nervure in hind wings broken above the middle 27 



Transverse median nervure in hind wings broken at or below the middle 30 



27. First abdominal segment ivitlt four strong elevations behind the middle. 



(514) Nitrcopa-a Forster. 

 First abdominal segment irilhout elevations behind the middle. 



Lower tooth of mandibles not longer than the upper tooth; i-lyj)eus 

 impressed or truncate anteriorly 28 



