FAMILY DOLIL'IIOPID.E THE LONG-HEADED FLIES 223 



Middle of propleura bare; third antennal segment rather triangular, 

 the arista apical (45, 81 ) *Paraphrosylus Becker 



49. Acrostical setulae present, though weak 50 



Acrostical setulas absent (14) fThinophilus Wahlberg 



50. Arista apical or practically so, sometimes arising a little above the 



tip of the pointed third antennal segment 51 



Arista dorsal 58 



51. Propleura bare or with a single bristly hair in the middle 53 



Propleura haired in the middle 52 



52. Second antennal segment produced thumb-like into the third on the 



inner surface (9, 84) JSynarthrus Lcew 



Second antennal segment not strongly convex apically (21, 47, 49). 



§Rhaphium Meigen 



53. Second longitudinal vein very strongly sinuous (65) (Eutarsus Aid- 



rich, Van Duzee, not Lcew) Diaphorus Meigen 



Second vein at most gently undulate 54 



54. Second antennal segment produced thumb-like into the third; abdo- 



men elongate and not tapering apically (35, 54). 



Parasyntormon Wheeler 

 Second antennal segment usually transverse, rarely strongly convex 

 apically, if so the abdomen short, cylindrical and tapering from base 

 to apex 55 



55. Body silvery white pollinose; middle of propleura with a single bristle 



( 64 ) Leucostola Lcew 



Bodj' rarely silvery pollinose; middle of propleura bare 56 



56. Lower section of face not differentiated 57 



Lower section of face strongly differentiated and large (45, 81). 



*Paraphrosylus Becker 



57. Fi'ont narrow, if wide the apex of the abdomen with four bristles 



(23, 75) IJDiaphorus Meigen 



Front wide, the face usually very narrow, the apical abdominal seg- 

 ment without strong bristles (13, 39) [[Chrysotus Meigen 



58. Second antennal segment produced thumb-line into the third on the 



inner surface (32, 50, 69) Neosyntormon, n. g. 



Second antennal segment transverse or gently convex apically 59 



59. Middle of propleura bare 60 



Middle of propleura haired 63 



60. Abdomen flattened dorsoventrally (2) °Campsicnemus Walker 



Abdomen not flattened dorsoventrailv 61 



• Van Duzee, 1924, Pan.-Pac. Ent., i, p. 73. 

 t Van Duzee, 1926, Ann. Ent. Soc. Amer. xix, p. 35. 

 J Van Duzee, 1925. Tr. Amer. Ent. Soc. 1, pp. 257-287 (Syntormon). 



§ Curran, 1926-1927. Tr. Roy. Can. Inst., xv, pt. 2, pp. 249-260; xvi, pt. 1, pp. 99-179. 

 T Van Duzee, 1922, BuU. Buff. Soc. Nat. Sci., xi, pp. 161-194. 



li Van Duzee, 1924, Bull. Buff. Soc. Nat. Sci., xiii, pp. 1-53; 1931, Amer. Mus. Novit. No. 

 483 (Neotropical) 



° Van Duzee, 1917, Ent. News, p. 124 ; Curran, 1933, Amer. Mu.s. Novit. No. 682, p. 5. 



