402 C. R. OSTEX SACKEN'S PRODROME 



existence of any other species with which to identify tlie description, render the synonymy 

 certain. In this species the oceUar tubercle is not visible ; the pubescence of the eyes in 

 the male is very distinct ; in tlie feniule very short, and often hardlj^ visilile. The colora- 

 tion of the eyes of the female (revived on wet sand) appeared not unlil;e that of T. tri- 

 jujiclus, caienatus, and that whole group : two bluish green stripes, with a rather broad 

 interval ; the lower stripe bent towards the upper one at the outer end, without, however, 

 reachino; it. 



o 



42. Tabanus cerastes n. sp. 



Female. E^-es pnlje.scent ; face white, with Avhite hair ; palpi rather stout, pale yellow, 

 with Avhite, mixed with a few black hairs; antenna? reddish, third joint very deeply ex- 

 cised, almost crescent-shaped, upper angle drawn out in a rather long horn, which, as 

 well as tho annulate portion of the third joint, is black; sometimes the whole joint, 

 except the Ixise, is brownish ; front moderately broad, grayish yellow ; callosity brownish 

 red, large, square ; a spindle-shaped Ijrown line above it is usually disconnected from it ; 

 (in my three specimens tliis line has a well marked groove in the middle, which ends in a 

 deep puncture on the callosity ; this may he a merel_y adventitious character of the species). 

 Thorax of a liglit chocolate lirown with whitisli lines ; pleura? whitish, with white hair. 

 Aljdomen of a light chocolate In-own, with wliite triangles in tlie middle, and rather large, 

 oblique, white spots on the sides. Venter densely clothed with whitish pollen, and with a 

 trace of a longitudinal In-own stripe. Feet reddish, whitish poUinose, and with white hairs ; 

 tips of til>ii\3 and all the tarsi brown. Wings snl>liyaline, faintly tinged witli brownish 

 between the root and the stigma ; first posterior cell broadly open. Length, 15-lG nnn. 



Ilah. Kentucky (Bee Spring, June, F. G. Sanborn) ; Wisconsin (E. Kennicott). 



Ihe long horn-like upper angle of the antenna^, as well as the peculiar brown coloring, 

 renders this species easily recognizable. T. -scltus Walker seems to have antenna^ of the 

 same structure ; in otlier respects its description is entirely unmeaning. The words " an- 

 tennes a dent un pen allongee," in Macquart's description of his T. lurtioculatiis 5 

 (Dipt. Exot., 5" Suppl., p. 33), together with the pubescent eyes, may indicate the unknown 

 male of my T. cerastes ; still the data of the description are not suthcient to wan-ant the 

 identification of the female. The eyes of an alcoholic female showed a single bluish stripe 

 hi the middle. 



C. Tabani with pubescent eyes and with an ocellar tubercle (subgenus Therioplcctes). 



43. Tabaiius flavipes. 



Tahanus fitiu'/ics Wieileitiinin, T, \>. I:i7, 41. 



Female. Eyes pubescent, face yellowish grny, with dense yellow hair on the cheeks ; 

 some blackish hairs below the eyes; palpi long and narrow, black. Antenna? dark red; 

 third joint black on its distal half, excised above, and with a projecting upper angle; front 

 rather broad, narrowed anteriorly, dark grayish ; callosity very convex, with a more or less 

 spindle-shaped prolongation above ; the subcallus in all my specimens is denuded, shining. 

 Thorax black, with black, erect pile, mixed with yellowish hairs, especially in front; ante- 

 alar tubercle black ; pleura? black, clothed with sparse yellowish hairs, which are denser 



