Nineteenth Annual Meeting. 137 



Tabanus susukkus Marten, Can. Entom. xv, 111. Montana. 

 Evidently allied to T. rhombicus [Therioplectes.) 

 A. Eyes pubescent, THERIOPLECTES. 



Tabanus affinis Kirby. 



A single, somewhat rubbed specimen, from Colorado, seems to be of this species. 



Tabanus bhombicus Osten Sacken. 



A number of species from Colorado agree so well with the description of this 

 species that I feel quite sure of my determination. They belong, however, in the two 

 groups described by Osten Sacken in his Western Diptera ( p. 218), agreeing well with 

 the characters there given, except that I can perceive no difference in the subcostal 

 cell. It would seem probable that there are distinct species among them, yet speci- 

 mens of the two forms were collected together in North Park. T. stisuri-us Marten 

 must be closely allied, though the prominent angle of the antenna? seems to indicate 

 a distinct species. 



Tabanus sequax, n. sp. 



Female: Length 14-16 mm. Front of nearly equal width, brownish, with black 

 pile; callosity squarish or subcordate, black; extending above into a line; subcallus 

 not denuded. Antennae wholly deep black, the annulate portion of the third joint 

 about three-tifths as long as the basal portion; angle obtusely pirojecting. Face 

 gray, with whitish pile. Palpi grayish black, with black hair. Dorsum of thorax 

 grayish black, with rather abundant, mostly black pile, and two not very distinct 

 grayish stripes anteriorly; a tuft of white pile on the post-alar callosities. Pleura? 

 with white pile. Abdomen black, the segments with a narrow hind border of whitish 

 dust and pubescence, interrupted on each side of the small median triangular ex- 

 pansion. Legs black, the base of four anterior tibiae faintly reddish. Wings hyaline, 

 the cross-veins and furcation of third vein with small but distinct brown clouds. 



Three specimens, Mt. Hood, Oregon. The eyes in this species are distinctly pu- 

 bescent, and the vertex has a partially denuded tract, though I cannot distinguish any 

 ocellar tubercle. 



Tabanus comastes, n.sp. 



Female: Length, 14-16 mm. Face yellowish-gray, with similarly colored pile. 

 Palpi moderately stout, yellow, with black hairs. Antennae red, the annulate portion 

 black, the basal joints more or less blackish; basal portion broad, a little longer than 

 the annulate portion, the angle moderately projecting. Front convergent anteriorly, 

 yellowish or grayish-brown, with black pile; callosity nearly square, black, subcallus 

 denuded, shining black; ocellar tubercle distinct. Dorsum of thorax grayish brown- 

 ish black, with fulvous pubescence and black pile; ante-alar callosity reddish. Pleurae 

 gray, with grayish pile. Abdomen black in the middle, exjianding anteriorly, and 

 on the fifth and following segments; broadly yellowish or brownish red on the sides; 

 the posterior margins of the segments (expanding a little in the middle of the an- 

 terior segments) lighter yellow, with a fringe of golden pile. Venter yellowish red, 

 black distally. Legs black, the base of the front tibite, and the four posterior femora 

 distally, their tibiae and tarsi (except their brownish distal parts), reddish yellow; 

 hind tibiae black ciliate. Wings nearly hyaline. 



Male: The basal portion of the third antennal joint narrower, more excised above, 

 and with the angle more drawn out. Eyes, thorax and legs more thickly pilose. 



Five females and one male from Washington Territory and Mt. Hood, Oregon. 

 The species resembles T. lasiophfhahmis, but will be at once distinguished by the 

 absence of brown clouds on the wings. The black on the second and third abdomi- 

 nal segments might better be described as forming two rounded or (|uadrate spots; 



