140 ENTOMOLOGICAL NEWS. [May, '19 



bits more or less differentiated above for a short distance, 

 and shortly above antennae with a transverse depression. Two 

 pairs of verticals, one of frontals, which are at the level of 

 the median ocellus. Post-verticals absent (in ours, said to be 

 divergent by Oldenberg). 



Thorax and abdomen in all the species black and highly 

 polished. Chaetotaxy of thorax: dc i, npl i, stpl i, sc i (and a 

 very minute lateral pair, apparently absent in the female of 

 slossonae} ; acrostichals in the North American species a very 

 delicate single row of hairs, laterad of which the surface is 

 entirely bare to another row in the dc line. Wing as figured, 

 second basal and anal cells wanting, fourth vein gently curved 

 forward from near the crossvein, so that the first posterior 

 cell is about two-thirds as wide at apex as near its base. 



Table of North American Species. 



Front and hind femora distinctly stouter than middle ones 



slossonae n. sp. 



Front and hind femora of about the same diameter as the middle 

 ones 



melanderi n. sp. 

 Leiomyza slossonae n. sp. 



Front brown, including an extension to the vertex on each side of 

 the ocelli ; ocellar triangle and the upper third of frontal orbits shining 

 black; lower edge of front yellow; antennae yellow, third joint, oval, 

 slightly infuscated or not on upper edge ; arista microscopically 

 pubescent, appearing bare under hand lens. Face, parafacials and 

 bucca almost white, sometimes more yellowish, with a narrow brown 

 line usually perceptible separating the first two and bordering the sides 

 of the mouth cavity. Palpi yellow ; proboscis small, yellow. Halteres 

 yellow. Legs including coxae wholly yellow except last tarsal joint, 

 which is brown ; front and hind femora thickened in both sexes, and 

 their coxae and trochanters a little elongated. Length 1.8 mm. 



Types, one male (holotype), one female, mounted on same 

 pin, from Franconia, New Hampshire, collected by Mrs. Slos- 

 son and in her possession. Paratypes, one each from Pullman, 

 Lyndon and Almota, Washington, and one from Moscow 

 Mountain, Idaho, all collected by Professor Melander. Para- 

 type from Washington deposited in the United States National 

 Museum. 



