NORTH AMERICAN DIPTERA. 255 



of the first joint brownish black, the base of the second is, however, lighter. 

 Wings pure hyaline, veins decidedly yellowish, third longitudinal vein in one 

 simple, in the other with an obsolete rudimentary branch, discoidal cell emits 

 two veins. 



9 . — Head yellow : occiput except the orbits black, front with four black spots, 

 upper spots together with the minute black spot on the vertex confluent ; thus 

 also is formed a band on each side, which touches the margin of the eyes ; the 

 lower spots are obliquely drawn out, subcontiguous in the middle of the front 

 and touching on each side the margin of the eyes. Face moderately prominent, 

 convex, and adorned with a triangular black spot, proboscis black ; palpi light 

 yellow ; dorsum of the thorax black, with a slightly golden tomentum, posterior 

 angles greenish yellow ; pleurae greenish yellow, with a large black spot, which 

 is connected with the black of the pectus; scutellum black, apical margin bi'oad, 

 spines small, greeuLsh yellow : the extreme points black. Abdomen black, mar- 

 gins of the segments separate ; lateral margins equal, posterior margins subequal, 

 greenish yellow ; venter totally greenish yellow. Legs yellowish (tarsi in the 

 specimen described wanting). Wing pure hyaline, veins strongly yellowish, third 

 longitudinal vein branched, discoidal cell emits two veins, fourth near the base 

 very thin. 



"Fort Resolution," Hudson's Bay Tevritory (Kennicot), Loew. 



0«loutoniyia arAuata Loew (PI. iii, fig. 35; PI. iv, figs. 7, 8). 



Odontomyia arcnata Loew, Centur. x, 4 ; Day. Proc. Acad. Nat. Sci. Phila. 



1882, 80. 



Length % 9 9-11 mm. %. — Face and inferior orbits light yellow; pile white, 

 an obscure transverse brownish line above the oral margin ; frontal and vertical 

 triangles black, ocelli yellow, proboscis black ; first and second joints of the an- 

 tennae red ; third dark brown, and narrowly annulated with black : dorsum of 

 the thorax shining black; pile yellow, sparse, but long and dense on the sides ; 

 posterior angles obscure brown, pleurse greenish yellow, pectus black ; scutellum 

 greenish yellow ; base black, spines yellow, tip brown. Abdomen green, with an 

 irregular black dorsal stripe, having the following contour: greatly contracted at 

 the margins of the second and third ; third and fourth, and the fourth and fifth 

 segments, mark on the fourth segment somewhat wider than those on the second 

 and thii'd ; mark on the fifth only extending to the centre of the segment, later- 

 ally attenuated: venter green. Legs yellow, tip of the first and the rest of the 

 joints of the tarsi brown. Wings pure hyaline, veins light yellow, discal cell 

 emits two strong veins, the other indicated only by au obsolete angle; third lon- 

 gitudinal vein branched. 



9 • — Face, front, vertex and occiput yellow, pile light yellow ; vei'tex and front 

 with a transverse baud of black, in the former not reaching the orbits, and some- 

 times narrowly extending in the middle over the vertical angle, in the latter 

 sometimes narrowly divided in the middle and the frontal fo.ssa is sometimes 

 black, connecting the frontal and vertical bands. In some specimens there is a 

 blackish, transverse marking abov*^ the oral margin, and in one specimen the 

 facial prominence and a small dot on each side is also blackish; ocelli yellow, 

 proboscis black ; first and second joints of the antennae red ; third dark brown. 

 Thorax black, with short, decumbent, golden-yellow pubescence, longer on the 

 sides ; posterior angles, pleurae and in one specimen a small spot at the suture, 



TKANS. AM. ENT. SOC. XXII. JULY, 1895. 



