474 Annals Entomological Society of America [ Vol. VI, 



97. Gray, posterior margin of abdominal segments grayish-brown. Hypopy- 



gium moderately large, ninth tergite broadly and deeply emarginate, 

 the margin notched in the middle, lateral angles produced into a 

 process, 'subtruncate at the apex, ninth sternite deeply divided 

 by a U-shaped incision, the latter containing a medium lobe-like 

 process, lateral margins of the incision emarginate, the upper angles 

 bearing a long pendulous process. Wings light grayish fuscous. 



Length 143^-153^mm infuscata Loew 



Not gray, posterior margin abdominal segments not paler 98 



98. Reddish yellow, smaller. Head ' and thorax whitish pollinose. 



Hypopygium very small, compressed. Wings pale fuscous, first basal 

 cell and margin of second a trifle paler. Length 13mm (cf) ... casta Loew* 

 Brown, larger. Thorax gray with four brown stripes; posterior margin 

 of eighth sternite f with a median tuft of yellow hair between a pair 

 of irregularly shaped, six-sided, box-like appendages; ninth tergite 

 with the posterior-lateral angles produced into two broad, truncate 

 projections; posterior margin of ninth sternite with rounded incision 



containing a pair of horn-like projections. Length 16-20mm 



flavocauda Doane 



99. A vitreous spot before the stigma 100 



Without such a spot 154 J 



100. Spot lunate, extending to or beyond the discal cell 101 



Spot small, never extending beyond the second longitudinal vein 145 



101. Joints of flagellum distinctly bicolorous 102§ 



Joints of flagellum approximately unicolorous 110 



102. Fuscous species; abdomen with three darker stripes; eight sternite 



with a median process 103 



Yellowish species, costal and subcostal cells yellowish 104 



103. Costal and subcostal cells brown. Mesonotum with four darker vittse; 



Posterior margin of abdominal segments paler; ninth tergite short, in- 

 cised in the middle. Wings hyaline, anterior margin of anal cell 

 fuscous, the whitish line before the stigma which extends into the 

 base of the fourth posterior cell, very indistinct. Length 



16-22mm pellncida Doane. 



clara || Doane, Syn. 

 Costal, subcostal and anterior margin of anal cells tinged with yellow. 

 Mesonotum with three dark vittae; lateral and posterior margins of 

 abdominal segments paler; hypopygium small, ninth tergite with 

 deep crescent-shaped incision, ninth sternite with deep U-shaped 

 incision, which contains two long, tumid appendages. ' The white 

 spot before the stigma reaches the extreme base of the fourth posterior 

 cell. Length 20-27mm inermis Doane. 



104. Abdomen with three dark, fuscous stripes, valves of ovipositor short, 



blade-like 105 



Abdominal stripes, if any, faint; if distinct, but one dorsal stripe 106 



105. Posterior margin of ninth tergite with a short, rather broad, two pointed 



process, posterior margin of eight sternite with fringe of yellow hair 

 and two strong, curved reddish bristles; ninth sternite with median 

 depression, in which lie the tips of two short appendages; the white 

 spot before the stigma reaches the posterior border of the discal 

 cell. Length, 15-18mm megaura Doane. 



* Probably the male of cunctans Say., and according to Osten Sacken, syn- 

 onymous. 



"(■Original description says, "tergite," evidently a misprint. 



JNot infrequently the space before or surrounding the stigma is paler than 

 the general color of the wing. 



§Antenna? of T. clara not described by its author. 



|| Prof. Doane does not mention the antennas. 



