64 DIPTERA OF NORTH AMERICA. 



9 < f Reticulation paler in the middle. 20 festiva, n. sp. 



I Reticulation everywhere of the same color. 21 bella, n. sp. 



f The curvature inside of the first posterior cell considerable. 

 ! 22 latifrons, n. sp. 



j The curvature inside of the first posterior cell very small. 



23 melanogastra, n. sp. 

 26 j Stigma fuscous. albidipennis, n. sp.* 



1 Stigma pale. alba, n. sp.f 



7. Description of the species. 



1. T. discolor LOEW. . (Tab. II, fig. 1.) Lutea, abdomine nigro, 

 alarum fasciis quatuor obliquis fuscanis, prima et secunda antice, tertia 

 et quarta postice connexis, vena longitudinal! tertia setosa, venulis 

 transversis valde approximatis. 



Luteous yellow with the abdomen black ; wings with four very oblique 

 brownish bands, the two first being anteriorly, two last posteriorly 

 connected ; third longitudinal vein with bristles and the two transverse 

 veins approximate. Long. corp. 0.13. Long. al. 0.15. 



Yellow with a rather glossy black abdomen, which color becomes 

 more blackish-brown near the base. Front proportionately rather 

 narrow ; three bristles at each side are of a browner color and 

 directed anteriorly. Antennae yellowish, not reaching as far as 

 the border of the mouth ; bristle of the antennae thin, apparently 

 naked. Face descending rather straight downwards, but little 

 excavated. Opening of the mouth proportionately large. Pro- 

 boscis short, palpi somewhat prominent. Upper side of the tho- 

 rax with short yellow hairs and yellowish-brown bristles; it has 

 no pale stripes, but there is an obsolete, paler, longitudinal stripe 

 between it and the pleurae. Pleurae of the color of the upper 

 side of the thorax, with yellowish bristles ; the neighborhood of 

 the coxss is blackish. Scutellum with four bristles. Abdomen 

 with short black hairs. Legs yellow, anterior femora with ochra- 

 ceous bristles on the under side. Wings glassy with four very 

 oblique brown bands, which are partly tinged with brownish- 

 yellow on the inside. The first band begins at the base of the 

 wing, where it is connected with the second, runs over the anal 

 cell as far as the base of the third posterior cell, and, including the 

 fourth longitudinal vein, projects a little, whereupon leaving the 

 latter, it bends towards the posterior border of the wing, which it 



* See Appendix III. t Ibid. 



