THE CANADIAN ENTOMOLOGIST. 143 



One male specimen taken by Mr. C. W. Johnson, at VVestville, N. 

 J., June 6. 



Though the genus Nematoproctiis has been abandoned by European 

 dipterologisls, it may be reinstated, at least provisionally, for this species 

 whose habitus is different from any North American Diaphorus with 

 which genus Nematoproctus has been united. The genus has never 

 before been recognized outside of Europe. 



9. Tachytrechiis volitans, n. sp. (Fig. 8.) 



Male. — Differs from Floridensis as follows : Front thickly covered 

 with brownish dust, face with ochraceous dust. First joint of antenna, 

 when viewed from behind, brownish; when viewed from the front, opaque- 

 black, except inner projection. Ground-colour of thorax of a brilliant 

 metallic copper-colour, which shines through the thick coating of brown 

 dust. Pleura and coxs heavier white-dusted. Hind femora dark up to 

 very tip. Pulvilli relatively longer, snow-white. Abdomen more cupre- 

 ous. Pedicel of hypopygium more slender; hypopygium with penis pro- 

 jecting, distinct ; lamellae of similar form, but without the long black basal 

 bristles, and evenly and closely fringed on outer side with longer hairs. 

 The spot at tip of wing arises at tip of third vein and passes back so that 

 the fourth vein bisects it. The third vein arches posteriorly at outer 

 fourth. The fourth vein bends backwards at tip. The posterior cross- 

 vein is less oblique and more sinuate. 



The female differs from the male in the same characters as in Flori- 

 densis. 



One male and one female, from twelve miles north-west of Lusk, 

 Wyoming; July, 1895 ; '^'^om the collection of the University of Kansas 



10. Tachytrec/ms p}-oierviis, n. sp. (Figs. 6, 7.) 



Male. — Length 4.25 mm., of wing 4 mm. Face narrowed in middle, 

 silvery dusted, yellower toward antennae. Antennae large, yellow ; first 

 joint short, second and third fully developed ; third joint rounded, infus- 

 cated above and toward tip, bearing the dorsal arista once and two-thirds 

 the length of the antenna. Vertex brownish-velvety. Post-ocular cilia 

 black above, pale yellow, slender below. Thorax piceous green ; above 

 the base of the wing the horizontal black velvety macule and anterior 

 silvery spot are present, above the former the dorsum is cupreous. Ab- 

 domen dark green, silvery-dusted along sides, incisures well marked. 

 Hypopygium piceous, lamellae subrectangular, dark, hairy, evenly fringed 

 with short black hairs, which are lighter dorsally toward base. Pleura 



