476 Annals Entomological Society of America [Vol. VI, 



115. Abdominal segments 6-8 mostly black. Mesonotum trivittate; ninth 



sternite with deep incision, containing a pair of yellow appendages; 

 wings hyaline, a faint brown spot over origin of praefurca, ante-stig- 

 mal spot broad, distinct, reaches base of fourth and side of fifth pos- 

 terior cell. Length 15-20 mm retusa Doane 



Abdominal segments 6-8 not black 116 



116. Mesonotal stripes and ante-stigmal spot distinct. Eighth sternite very 



large with median, rectangular projection of the posterior margin; 

 ninth sternite with deep U-shaped incision, containing a long, rather 

 broad tumid process; pleural plates distinct; fifth vein narrowly bor- 

 dered with brown. Length (cf ) 22 mm_ spatha Doane 



Mesonotal stripes and ante-stigmal spot very indistinct. Eighth sternite 

 long, narrowed posteriorly; posterior margin of ninth sternite with 

 two processes, each bearing a tuft of hair, lateral margins with two 

 pairs of appendages. Length (o^) 12 mm sphndens Doane 



117. Ante-stigmal spot extends to posterior margin of wing; posterior mar- 



gin of abdominal segments 1-7 pale yellow. Joints of flagellum brown, 

 yellow at the base. Mesonotum with three broad, reddish brown 

 stripes. Abdomen trivittate, segments 8-9 wholly brown. Wings 



nearly hyaline. Length ( 9 ) 20 mm albofascia Doane 



Ante-stigmal spot does not reach the posterior margin of wing. Abdo- 

 men with three stripes, posterior margin of segments 4-8 white; ninth 

 tergite with deep, median impression bearing at its end a rather 

 broad, sharp pointed process; ninth sternite with deep, white bor- 

 dered incision which contains two pendulous appendages. Wings 

 hyaline, a whitish spot beyond the stigma and two whitish, indistinct 

 streaks just behind the sixth longitudinal vein. Length (o^) 19 mm. 



alhocincta Doane 



118. A whitish spot beyond the stigma. Joints of flagellum darker at the 



base; thrfee broad mesonotal stripes; three indistinct abdominal 

 stripes; lateral angles of eight sternite with a pair of rather broad 

 appendages; ninth tergite thick swollen with median shallow furrow, 

 posterior margin produced each side into a blunt, swollen process, 

 deeply emarginate between the processes; ninth sternite with rounded 

 incision which is filled by two long triangular appendages. Wings 

 hyaline; the ante-stigmal spot extends into the base of the fourth 



posterior cell. Length 21 mm. (cf) hirsuta Doane 



Without whitish spot beyond the stigma 119 



119. Mesonotal vitt^ obsolete or very faint; abdominal stripes and ante- 



stigmal spots ill defined or indistinct 120 



Ante-stigmal spots at least distinct 121 



120. Larger, 18-20 mm., thorax yellow, shining, no stripes. Flagellum 



brown; posterior margin of eight sternite* with two tufts of long hair; 

 hypopygium large; posterior margin of ninth tergite with slight 

 median incision, lateral angles produced into short, slender acute 

 points; ninth sternite with rather deep incision containing a pair of 



short appendages. Wings hyaline lucida Doane 



Smaller, 12-13 mm. Flagellum brown; thorax not shining, stripes very 

 faint brownish. Kinth tergite nearly completely divided, each side 

 terminating into a point, bent at right angle to upper surface. Ninth 

 sternite long, posterior margin with two small processes, each bear- 

 ing a tuft of hair. Wings hyaline lamellata Doane 



121. Abdomen with three black stripes; ante-stigmal spot distinct; flagellum 



dark fuscous ' 122 



Abdomen without such stripes; thoracic stripes very faint; ante-stig- 

 mal spot distinct extending to base of fourth basal cell 123 



"In the description it says "tergite," no doubt by misprint. 



