336 THE CANADIAN ENTOMOLOGIST. 



3. Ocelli present, scutellum smooth, bearing a row of bristles in front of 



the hind margin, the latter bare Ornithomyia, Latr. 



Ocelli wanting, hind margin of scutellum roughened with many nearly 

 vertical ridges and fringed with bristles, scutellum otherwise bare. 

 (Type: Ornit/iomyia/u/vifroiis, Walk.) Sii/boinetopa, n. gen. 



4. Anterior angles of thorax projecting forward in the form of long 



tubercles 5. 



Anterior angles of thorax rounded Hippobosca, Linn. 



5. Clypeus one-half as long as the middle of the front, scutellum bearing 



a stout bristle near each lateral margin Olfersia, Wied. 



Clypeus almost as long as the front, scutellum bare. (Type: F. maculata, 



n. sp.) , . . Pseudolfersia, n. gen. 



Pseiidolfersia maculata^ n. gen. et sp. Front yellowish brown, the 

 polished lateral margins and vertical triangle dark brown, the latter taper- 

 mg anteriorly, broadly rounded at the tip, almost reaching the lower end 

 of the front, a black bristle each side of the vertex and a row of smaller 

 yellow ones on each side of the lower two-thirds of the front inside 

 of the polished lateral margins ; clypeus brown, yellowish medially, 

 polished, noticeably longer than broad, notched in the middle of the apex 

 and sulcate in the middle, the sulcus terminating in a deep fovea near the 

 base of the clypeus ; antennee brown, subovate but flattened above, lying 

 in deep grooves, not reaching apex of the clypeus, polished except the 

 inner portion of its upper side which is opaque gray pruinose, bearing to- 

 ward its apex a few yellow hairs and many long black bristles ; palpi 

 brown projecting slightly more than their greatest width beyond the apex 

 of the clypeus ; under side of the head brown, a yellow median longitud- 

 inal sulcus, and a rather large white lobe at its anterior end. Thorax 

 dark brown, polished, the humeral tubercles apically yellow, a spot at 

 inner side of each, another a short distance back of it, a stripe reaching 

 from the prothoracic stigmata to base of wing, the transverse suture and 

 a pair of spots on the posterior end of the thorax opaque gray pruinose, 

 no median longitudinal sulcus, the transverse sulcus interrupted in the 

 middle ; pleura thinly gray pruinose except three spots along the suture in 

 front of vvings, sternum polished except its extreme anterior end which is 

 gray pruinose; scutellum polished brown, truncate posteriorly, bare except 

 a short pubescence along the posterior margin. Abdomen opaque gray- 

 ish brown, the apex and venter yellow. Wings smoky brown, apex of 

 auxiliary vein slightly beyond apex of second basal cell, that of first 

 vein slightly beyond ai)ex of first basal cell, of the second vein near- 

 ly midway between the apices of the first and third veins ; first two 

 sections of fourth vein subequal in length. Legs polished brown, front 

 coxge anteriorly opaque gray pruinose, pulvilli yellow, basal tooth of each 

 tarsal claw yellowish. Length 7 to 8 mm. Wisconsin, on a Loon ; also 

 without indication of locality, on an Osprey, Paiidion haliactus carolinensis. 

 April 30, 1883. Nine specimens. Type No. 421 i,U. S. Nat. Museum. 



Mailed November i5tli, 1S99. 



