124 DIPTERA OF NORTH AMERICA. [PART III. 



immature specimens. Feet of a dirty clay-yellow, femora in the 

 middle and tarsi towards the tip, somewhat infuscated. Halteres 

 whitish-yellow. Wings whitish-hyaline, with three broad, perpen- 

 dicular, more grayish-black than black crossbands. The first of 

 these bands covers, near the anterior margin, the latter half of the 

 costal cell, and reaches, without becoming more narrow, the fourth 

 or fifth longitudinal vein; in the first case it becomes perceptibly 

 paler between the third and fourth, in the second case between 

 the fourth and fifth longitudinal veins. The second band covers, 

 near the anterior margin, the apical half of the stigma and reaches 

 there, in most specimens, even a little beyond the end of the first 

 longitudinal vein ; without attenuating, it runs over the small 

 crossveins as far as the fourth longitudinal vein, forms a very 

 broad border along the section of the fourth vein lying between 

 the two crossveins, and runs, afterwards, along the posterior 

 crossvein towards the fifth longitudinal vein; its breadth is not 

 the same in all specimens; when narrower, this crossband shows 

 a distinct knee-shaped bend, depending upon its passage from the 

 small to the posterior crossvein (this is the case with the specimen 

 figured by Mr. v. d. Wulp) ; when broader, this crossband 

 extends, in the shape of a blackish-gray shadow, as far as the 

 third posterior cell, so that of the knee-shaped bend only a trace 

 is left, which is due to a diluted spot upon the inner side of the 

 crossband, near the posterior margin. of the discal cell (as repre- 

 sented in my figure). The third band covers, on the anterior 

 margin, the end of the marginal cell to a considerable extent, 

 becomes gradually more narrow posteriorly and reaches more or 

 less completely the fourth longitudinal vein, where it suddenly is 

 interrupted. The root of the wing is tinged with blackish-gray 

 as far as a little beyond the humeral crossvein. The second and 

 third longitudinal veins are strongly divergent towards their 

 end ; the last section of the fourth longitudinal vein slightly con- 

 verges towards the third vein and is not quite so straight as usual 

 in the species of Tephroriota, but, at the same time, not so much 

 curved forward by far as in the case of the species of Anacampta, 

 Holodasia, and Jpospasmica. The crossveins are very much 

 approximated, as the distance between them is not much larger 

 than the length of the small crossvein, but smaller than the 

 posterior crossvein. The posterior angle of the anal cell is short 

 and sharp, and not prolonged in the shape of a lobe. The sixth 



