SNOW: DIPTERA OF COLORADO AND NEW MEXICO. 229 



seen from behind mostly black. Scutellum destitute of long pile or 

 bristly hairs. Abdomen altogether shining, with short light pile. 

 Legs wholly black. Wings brownish, clearer toward the tip; veins 

 fuscous; stigma indistinct. Tegulse fringed with white pile. — Length 

 6 mm. 



One specimen, Manitou, Colo. (July). 



The species is perhaps nearest C. nigripe7i7iis Will., but differs in 

 the protuberant face, lack of black pile on the face, the pubescent 

 arista, the black color of the third antennal joint, and the white 

 tegular fringe. 



Chilosia, sp. 



An injured female specimen, Colorado (Gillette, No. 1680), cannot 

 be identified as previously described. Its general color is a brassy 

 black. Eyes bare. Facial tubercle very obtuse and the concavities 

 shallow; the face gradually projects from the antennee to the epistoma. 

 Pile of whole body short and sparse, light in color. Scutellum with- 

 out bristly hairs. Legs black and reddish. Wings brown. 



Melanostoma stegnum Say. 



Nine specimens, Manitou Park, Colo. (August); seven, Estes Park, 

 Colo. (July and August), all males. A single female, Colorado 

 (Gillette, No. 1722). A southwestern species. 



Melanostoma coerulescens Will. 



Two males, Estes Park, Colo. (August). Known only from Colo- 

 rado. 



Melanostoma concinnum, n. sp. 



Melanostoma, n. sp. '.' Snow, Kans. Univ. Quart. I, p. 35. 

 Male. Bluish or greenish metallic. Head dark blue, shining. 

 Vertical triangle with white pile; frontal triangle with long, erect, 

 dusky pile, and whitish pollen. Face prominent, with blackish pile, 

 and thin white pollen, not or scarcely concave between antennae and 

 tubercle; tubercle and epistoma blackish, bare, both very distinct, 

 about equally prominent; the pollen of the face is thin, not ripple-like 

 or distinctly dotted; face in the middle without parallel transverse 

 grooves, or wrinkles. Antennae black; third joint yellowish below, 

 oblong, as long as the two basal joints together. Thorax metallic 

 dark blue, more bronze black on the dorsum behind the suture. 

 Abdomen very narrow, widest at base, thence decreasing gradually in 

 width to the tip, though often the third segment posteriorly is slightly 

 wider than the second segment posteriorly. The color of the ab- 

 domen can best be described as shining metallic bluish green; the 



