June, i9i6.] SwENK : NORTH AMERICAN HlPPOBOSCID^. 133 



Clypeus basally one half as broad as the distance across emargina- 

 tion ; length to end of wings 7 mm. 



Front distinctly less than twice as broad as an eye ; scutellum 

 with a copious, long, apical fringe intertropica. 



Front about twice as broad as an eye ; scutellum with a very 



thin, short, apical fringe albipennis. 



Clypeus basally about one third as broad as the distance across 

 emargination ; length to end of wings 7.5—8 mm. 



Mesonotum and scutellum blackish-brown ; orbital margins shin- 

 ing, glabrous botaurinorum. 



Mesonotum dark brown, scutellum yellowish ; orbital margins 

 opaque, hairy SCUtellaris. 



8. Ornithomyia buteonis new species. 



Length 7—7.5 mm. Head yellowish-brown, the broadly crescentic orbital 

 margins and the vertex polished, the median area opaque. Clypeus convex, 

 slightly emarginate and rather weakly pitted anteriorly and bearing a small, 

 round pit on the posterior margin. Antennary processes distinctly less than, 

 twice as long as broad, clothed with bright pale ferruginous hair, broadly 

 lanceolate owing to both margins being evenly convex, the tips narrowly 

 rounded. Eyes light brown. Thorax above fuscous brown, paling to tes- 

 taceous on the humeral angles, the inner margins of the dentiform processes 

 and the adjacent spiracle whitish. Mesoscutum with a feeble median impressed 

 line and deep, sinuate, lateral median transverse impressed lines. Scutellum 

 fuscous brown, strongly tinged with reddish on the anterior margin, discally 

 shallowly depressed, and bearing a row of about a half dozen short black 

 hairs near each margin. Under side of head and thorax pale testaceous, the 

 labium whitish at tip. Legs above reddish-brown, below pale testaceous, the 

 tibiae with the edges fuscous, the tarsi fuscous, the claws black. Abdomen 

 yellowish, copiously but not densely clothed with short, black hairs. Wings 

 clear, the costal veins and bases of the longitudinal veins dark brown, the first 

 longitudinal vein ending in the costa at a point nearly above the first cross- 

 vein, the costal border of the marginal cell about one fourth longer than the 

 costal border of the first submarginal cell and the first basal cell more than 

 the length of the second crossvein longer than the second basal cell. 



Type. — Neligh, Nebraska, April 26, 1900, on a broad-winged hawk 

 (Bittco platyptenis) by Merritt Gary. 



Paratypc. — Guapiles, Costa Rica, March i, 1903, by J. C. Crawford. 

 Belongs to the O. erythroccphala group. Agrees with O. erythro- 

 ccphala Leach, of Brazil to Mexico and the West Indies, in size and 

 venation, but differs in the reddish-brown rather than ferruginous 

 head, the concolorous clypeus, the darker legs and the reddish an- 

 terior border of the scutellum. O. ncbnlosa Say, from the western 

 United States, is of the same size, but differs in the clypeus being pale 



