146 THE CANADIAN ENTOMOLOGIST 



half as long as the width of stigma; second discoidal cell closed at 

 the apex or nearly so. Abdomen broadly oval, the first dorsal plate 

 rather thick, with precipitous edges and finely wrinkled, slightly 

 wider at apex than at base and distinctly longer than broad ; second 

 segment two times as wade at apex as at base, smooth like the fol- 

 lowing segments; ovipositor slightly exserted. 



Clypeus, mandibles, palpi, scape, tegula?, base of wings, legs 

 except apical joint of the tarsi, and abdomen except the first dorsal 

 plate pale testaceous; apical joints of all tarsi, and the flagellum 

 brown-black; wing veins and stigma brownish; remainder of the 

 body black. 



Male. — Essentially like the female, but with the antennae 33- 

 jointed in type. 



Type locality. — Salt Lake, Utah. 



Host. — Agromyza parvicornis. 



Type No. 15591, United States National Museum. 



One female and five male specimens from the type locality, 

 labelled Webster, No. 8819. — C. N. Ainslie, collector. 



Probably closest to 0. hrmieiventris Cr. of the described species, 

 but readily separated from that species by the fact that in bninei- 

 ventris there is a distinct opening between the clypeus and man- 

 dibles, and the mesopleurae are smooth and polished except for the 

 oblique, foveolated furrow below the middle. 



Opius suturalis, n. sp. 



Male. — Length, 1.25 mm. Head transverse, smooth, with few 

 hairs above; the face only slightly hairy; clypeus arcuate, leaving 

 a transverse elliptical opening between it and the mandibles; an- 

 tennae pubescent, twice as long as the body, 22-jointed in the type. 

 Thorax smooth and shining; mesonotum without a median depres- 

 sion posterior y, the parapsidal furrows indicated only at the an- 

 terior lateral angles of the mesonotum; mesopleurae smooth, with 

 a shallow, ovate, non-foveolated impression below the middle; 

 propodeum smooth and polished. Wings thickly ciliated; the 

 stigma lanceolate, emitting the radius before the middle. The 

 first abscissa of radius short, third abscissa attaining the wing 

 margin far before the extreme wing apex; second discoidal cell not 



