1913] The North American Species of Tipula. ^75 



Posterior margin of ninth tergite with a small, subquadrate median 

 emargination, the external posterior angles extend as upturned, 

 hornlike processes, ninth sternite nearly concealed by the eighth, 

 bearing on each lateral posterior angle an incurved, clawlike process. 

 The white spot scarcely reaches the extreme base of the fourth posterior 

 cell. Length 12mm bicornis Loew Mss. 



106. Thoracic vittae and dorsal stripe of abdomen distinct; length 10 mm. 



puncticornis Macg. 

 Thoracic vittae obsolete or indistinct 107 



107. Joints of flagellum fuscous, yellow at the base; a transverse fuscous line 



before the posterior margin of the abdominal segments; abdomen 

 with lateral fuscous stripe; white ante-stigmal spot very distinct but 

 extends as a very faint line to discal cell. Ninth tergite quadrate, 

 posterior margin slightly emarginate in the middle with two central, 

 digitiform processes; ninth sternite small; pleural suture present. 



Length 12-18 mm. tephrocephala Loew 



Joints of flagellum yellow, fuscous at the base; abdominal segments 

 without transverse striae before the posterior margin; lateral angle 

 of eight sternite with a single or a pencil of two or three setae; lateral 

 angle of ninth tergite ending into a sharp point 108 



108. Thoracic vittae obsolete; posterior margin of abdominal segments gray; 



the white ante-stigmal spot does not enter the fourth posterior cell. 

 Length 15 mm. (cf). Ninth sternite emarginate, the emargination 



containing two pendulous processes translucida Doane 



Thoracic vittas not obsolete, though indistinct; posterior margin of 

 abdominal segments not paler 109 



109. The white ante-stigmal spot does not reach the posterior margin of the 



discal cell. Ninth sternite as in translucida, no white spot beyond 



the stigma. Length 16 mm. (a 71 ) cincticornis Doane 



The white ante-stigmal spot extends into the base of the fourth pos- 

 terior cell. Ninth sternite as in translucida; a white spot beyond the 

 stigma. Length 15-17 mm cuspidata Doane 



110. Yellowish species . . .' Ill 



Brownish-yellow species 124 



Grayish or fuscous species 129 



Blackish species (Northern) 142 



111,. The ante-stigmal spot does not extend into the discal cell. Mesonotum 

 with three broad, dark brown vittae; abdomen trivittate; eight ster- 

 nite produced and narrowed posteriorly; ninth tergite very small, 

 produced into two blunt processes posteriorly; ninth sternite large, 

 lateral angles produced into long, "tapering, twisted, hornlike pro- 

 cesses. Length 13-14 mm streptocera Doane 



The ante-stigmal spot extends into or across the discal cell 112 



112. Posterior margin of some or all abdominal segments paler 113 



Posterior margin of abdominal segments not paler 118 



113. Posterior margin of all the segments paler 114 



Some segments without pale posterior margin 117 



114. Abdomen with three well marked brown stripes. Mesonotum with five 



brown lines; joints of flagellum brown, darker at the base; lateral 

 angles of eight sternite with two incurved reddish bristles; ninth 

 tergite with deep broad, crescent-shaped incision; ninth sternite with 

 deep V-shaped incision, below which is a whitish, oval process. Wings 

 hyaline ante-stigmal spot very indistinct, but reaches the base of the 

 fourth posterior cell. Length 18-22 mm - bisetosa Doane 



Abdomen yellow, darker posteriorly but without longitudinal stripes; 

 flagellum brown; ninth tergite with deep V-shaped incision 115 



Abdomen reddish yellow, three indistinct stripes. T. lamellata, see 119. 



