224 NORTH AMERICAN TRYPETINA. 



of a very moderate breadth ; the usual frontal bristles black, only 

 the upper ones rather long and strong. The yellow antenna? 

 almost as long as the face ; arista long and slender, with a very 

 short and delicate pubescence. Oral opening rather large ; oral 

 edge rather sharp. Proboscis and palpi yellow, the latter rather 

 broad ; the suctorial flaps somewhat prolonged. The upper side 

 of the thorax of a light, bright clay-yellow ; a sulphur-yellow 

 middle stripe, gradually vanishing anteriorly, expanding poste- 

 riorly in a cuneiform shape, and nowhere well defined; scutellum 

 sulphur-yellow; on each side, above the root of the wings, a 

 well-marked pale-yellow longitudinal stripe, which runs from the 

 transverse suture to the posterior margin of the thorax ; quite 

 on the lateral margin an indistinct, but broader pale yellow stripe ; 

 the humeral corner and a well-defined stripe on the upper part of 

 the pleurae, reaching to the root of the wings, likewise of a bright 

 pale yellow. The very short pile on the thorax is yellowish ; the 

 usual bristles are black or blackish-brown. Scutellum with four 

 black bristles. Metathorax clay-yellow. Abdomen with short 

 yellowish pile and with black bristles on its posterior end ; the 

 last segment very much prolonged, much longer than the two 

 preceding ones taken together (this character serves easily to 

 distinguish this species from T. fraterculus, which is very much 

 like it). Feet yellow ; under side of the front femora with several 

 blackish-brown bristles. Wings not very broad in comparison to 

 their considerable length ; the rivulets upon them are pale 

 brownish-yellow with narrow, but little conspicuous, and not 

 always perceptible brown borders ; near the posterior margin and 

 on the apex of the wing they are altogether brownish ; the hyaline 

 spaces between the rivulets are as follows : 1. An oblique band, 

 interrupted upon the third longitudinal vein, the anterior part of 

 which forms, immediately beyond the stigma, a spot extending 

 from the costa to the third longitudinal vein, while the posterior 

 part of the band occupies the portion of the basal cell which lies 

 under the stigma, the basis of the discal cell and the second basal 

 cell ; 2. A broad S-shaped band which begins at the posterior 

 margin, between the tips of the fifth and sixth longitudinal veins, 

 passes between the two crossveins, reaches the second longitudinal 

 vein, turns backwards and reaches the margin in the vicinity of 

 the end of the fourth longitudinal vein ; 3. A large triangular 

 spot near the posterior margin, which fills a considerable part of 



