ameri(;an diptera. 259 



legs rufous in the female, aud venter, hind tibiae and tarsi black 

 also in the male. There is a complete gradation in specimens from 

 a single locality. 



OCYHROMIA Meigen. 

 Rather small, slender, almost glabrous species of black or reddish 

 color. Antennjfi shorter than the head, three jointed, the third 

 joint oval, with an almost terminal, dorsal bristle. Proboscis short; 

 palpi small, bare. Eyes glabrous, contiguous in the male, subcon- 

 tiguous in the female. Thorax prominent; abdomen lengthened, 

 femora and tibiae simple. Wings with a simple third vein ; a discal 

 cell present, emitting two, and often a rudiment of a third, veins to 

 the wing margin. Anal cell shorter than the second basal. Anal 

 angle oblique, rounded. 



Ocycironiia glabricnla Fallen (Figs. 66, 67). 

 Ocydromia glabricula Fallen, Emiiidiclse, 33, 42 (1816). 

 Ocydromia perigrinata Walk., List, etc., iii, 488. 



This species, which offers about a half dozen color varieties in 

 Europe, is present in the United States as the following variety, 

 described from ten specimens collected in widely distant localities : 



Very shining; black above, more or less reddish below. Mouth parts and an- 

 tennse black. Occiput less shining than the thoracic dorsum. Margin of the 

 scutellura, the humeri, pleurse, coxae and the ventral incisures of the abdomen 

 more or less reddish. Legs yellowish red, more or less fuscous above, at the 

 apices of the tibiae and on the tarsi. Halteres fuscous. Wings hyaline, more or 

 less infumated. Veins fuscous, somewhat reddish at the base. Anal vein almost 

 reaching the wing margin, the cross-vein nearly perpendicular to it. Outer ante- 

 rior bend of the discal cell with the fourth vein faint. Legs hairy, the hairs a 

 little denser on the inner apical third of the male hind tibiae; scutellum with 

 two apical bristles ; dorsum of the thorax almost glabrous ; abdomen subglabrous ; 

 hypopygium black, small, with a few hairs. 5 mm. 



Wisconsin, Wyoming, Vancouver Island. Ten specimens. 



BRACHYSTOMA Meigen. 

 Almost glabrous species of brown-black color. Antennae three- 

 jointed, diverging. Proboscis shorter than the head, thick, vertical. 

 Eyes of both sexes separated, but approaching beneath the an- 

 tennae in the male. Thorax large ; abdomen slender, lengthened, 

 in the male the genitalia are somewhat exposed, in the female the 

 abdomen ends in a large, semi-transparent, bladder like, peculiar 

 organ, in the lower side of which the ovipositor is enclosed. Wings 



TRANS. AM. ENT. SOC, XXVIII. AUGUST, 1902. 



