470 Annals Entomological Society of America [Vol. VI, 



69. Thoracic stripes not margined *70 



Thoracic stripes margined 76 



70. Apical third of wing infuscate; yellowisli-gray; abdomen trivittate, lat- 



eral margin and posterior margin of segments whitish; ovipositor 

 with a semi-tubular process each side at base. The white spot in 

 front of the stigma extends across the wing and attains the posterior 



margin; base of third posterior cell white. Length 19-20 mm 



valida fLoew 

 Apical third of wings not infuscate 71 



71. Abdomen black or orange colored. . . ._ 72 



Abdomen not so colored 73 



72. Abdomen blackish, posterior margin of segments yellow. Black; hypo- 



pygium small, posterior margin of ninth tergite depressed with two 

 median, longitudinal, shining black ridges; ninth sternite with a broad 

 deep incision. Wings grayish-brown, rhomboidal, discal and fourth 



posterior cells almost wholly white. Length 14 mm. (c?) 



helvocincta Doane 

 Abdomen orange-yellow with three black, longitudinal stripes. Wings 

 brownish, yellowish toward the costa, with about four whitish spots, 

 first and fourth posterior cells whitish at base. Length 15J^ mm. ( 9 ) 



versicolor JLoew 



73. Posterior cells not at all white. Head and thorax blue-black; stripes 



cff latter indistinct; abdomen brownish yellow, first segment black, 

 with brown lateral stripes; ninth tergite with broad, deep, crescent 

 shaped incision; ninth sternite with deep, V^-shaped incision, almost 

 separating the segment; pleural plates distinct. Wings with four 



indistinct, whitish spots. Length 16 mm. (cT) tiigrocorporis Doa.ne 



One or more posterior cells at least partially white 74 



74. Abdomen with median stripe. Brown; thorax with five stripes, § lat- 



eral pair confluent before and behind; a lateral black spot on each 

 abdominal segment; whitish spots along costal border distinct, those 



of disc indistinct, a small brown spot near the tip. Length 20 mm 



dorsimacida Walker 

 Abdomen without median stripe 75 



75. Posterior cells one and four white at base. Pale ochreous. Hypopygium 



moderate, ninth tergite short with two linear processes in the middle 

 of the posterior margin, eight sternite protuberant, emarginate at 

 apical margin and with lateral, leaf like process each side; ninth tergite 

 with apical V-shaped emargination, pleural suture short. Wings 

 grayish, apex a little darker, with about four not very distinct, whit- 

 ish spots. Length 12 mm pallida Loew 



First posterior cell only, white at base. Grayish; thorax grayish white. 

 Wings with several whitish spots. Length 12 mm. ($)... .ignobilis Loew 



*T. impudica see 121. 



fMr. C. P. Alexander informs me that he has seen the type of T. valida, a female, 

 in the Loew collection at Cambridge and that it is identical with specimens of T. 

 calva, in my collection, determined as such by Prof. Doane. The t3'^pe of the 

 latter species was a male. Specimens of both species — determined as such by 

 Prof. Doane and Mr. C. P. Alexander respectively — apparently agree in all par- 

 ticulars, except in coloration of the flagellar joints, which are distinctly bicol- 

 ored in calva and nearly fuscous in valida. There is also a difference in the 

 apical appendages of the two species. Loew does not mention the narrowly infus- 

 cate posterior transverse, and apical posterior of fifth veins. 



|Type, a female, minus antennae. 



§ In all probability it should read; thoracic stripes concolorous, margined. 



