126 Journal New York Entomological Society, t^'o'- ■-'^^"^iv, 



DESCRIPTIONS AND RECORDS OF NORTH 

 AMERICAN HIPPOBOSCID^. 



By Myron H. Swenk^ 

 Lincoln, Nebr. 



I. Olfersia albipennis Say. 



1S23. Olfersia albipennis Say, Journal of the Academy of Natural 

 Sciences of Philadelphia, III, p. 102. 



Length 5 mm., the head and thorax alone measuring 2.75 mm., and the 

 distance from the front of the head to the tip of the wing measuring 7 mm., 

 the thorax being 2 mm. wide at the widest part. Head and thorax blackish 

 brown. Head elliptical, nearly one and one half times as wide as long, the 

 face about twice as broad as the eyes and narrowing anteriad, the rather 

 broad orbital margins and the semicircular, uniformly convex vertex smooth 

 and polished, leaving a subtrapezoidal, opaque median area. Inner edges of 

 the polished orbital margins more or less hairy. Clypeus seven tenths as long 

 as the front, usually rather shiny, divided into two sections by a deep, 

 median, transverse sulcation, the apical section rather broad and anteriorly 

 broadly and shallowly emarginatc, so that its visible basal width along the 

 dividing sulcation is fully one half of the distance across the emargination 

 between the lateral apices. Antennary processes brownish black and bearing 

 long ferruginous and black hairs. Palpi blackish, subequal to the clypeus in 

 length, copiously clothed with short, pale hairs. Eyes shining blackish. 

 Humeral processes short and heavy, their tips obtuse, in color a yellowish 

 testaceous distinctly paler than the coloration of the rest of the thorax above, 

 bearing several short blackish hairs and one long black bristle. Mesonotum 

 with a distinct, impressed, median longitudinal line and straight, deep, trans- 

 verse, median sulci which are but slightly if at all interrupted medially, the 

 whole having a distinct cruciate form. Mesonotum anteriorly with a very 

 few, long, pale ferruginous hairs. Scutellum posteriorly broadly rounded, its 

 apical margin finely rimmed and thinly provided with short, pale hairs, a 

 deep median longitudinal sulcus giving it a sub-bilobed appearance. Pleura 

 opaque and grayish because of a thin pollinosity over the dark brown integu- 

 ment. Under side of head brown, the labium whitish. Sternum flat, shining 

 dark brown, the anterior angles prominent and extending as short, contrast- 

 ingly black lobes between the anterior coxas. Legs dark brown, below finely 

 pale-haired, above sparsely black-haired, the claws black. Tergum light 

 brown, darkening laterally, the base and apical portion together with a medio- 

 apical stain, blackish, venter light brown, the whole abdomen thinly short- 

 haired, these varying in color from pale at the base to blackish toward the 

 tip of the abdomen, tergum with two latero-apical tufts of long, black hairs. 

 Wings whitish, the costal \eins and basal part of the longitudinal veins dark 



