454 C- R- OSTEN SACKEN'S PRODROME 



by the vvliite color of the base of the front tibiaj, the blackish or brownish, and not ferru- 

 ginous brownissh, wingp, the absence of distinct white lines on the thorax, etc. The head 

 of the male is much larger than in T. nigrescens, and the large facets occupy much more 

 surface. 



30. Tab anus stygius. 



Tabanus stygius Say,Joiiin. Acad. PliiL, III, p. 33, 3; Wiedemann, Auss. Zw., I, p. 131, 31. 



Female. Frontal callosity much longer than broa^l, chestnut brown, with a spindle- 

 shaped prolongation above. Front brown ; a grayish spot on the vertex ; face yellowish 

 brown ; palpi black ; antennne dark reddish brown, annulate portion of third joint often 

 darker ; third joint much excised, and the upper angle very salient. Thoracic dorsum (in 

 well preserved specimens) clothed with a white j^Hen, through which the brown ground 

 color is but little apparent ; longitudinal white lines very distinct ; a short white jiubes- 

 cence makes tiio dorsum appear still whiter. Pleurae and pectus dark brown or blackish 

 brown, in sharp contrast with the white thoracic dorsum. Abdomen black, subopaque ; 

 venter black or dark brown. Legs black or dark brown ; front tibia^ slightly reddish at 

 the base. Wings strongly tinged with ferruginous brownish ; a brown spot on the bifur- 

 cation of the third vein, and a small cloud on the crossvein at the base of the second 

 posterior cell, more or less prolonged on the next crossvein. Length, 20-22 mm. 



Ilab. Connecticut (Southington, July, W. IL Patten); Pennsylvania; Maryland 

 (Am. Ent. Soc.) ; Illinois (Le Baron); Iowa (Dallas Co., Jefferson Co., J. A. Allen); 

 South Carolina (Sea Islands, June 2d, B. P. INIann) ; Florida (in the spring, E. Palmer). 



Say must have had a denuded specimen, as the characteristic white coloring of the tho- 

 rax is not mentioned in his description ; Wiedemann's is more explicit. The eyes (as far 

 as I saw them on an alcoholic specimen from Florida) are dark green with two dark pur- 

 plish bands and the vestige of a third above ; therefore similar to the eyes of 7\ nigrescens. 



31. Tabanus atratus. 



Tahmms atratus Fabricius, Syst. Entom., ]i. 789,9; Entom. Sy.st., IV, p. 3G6, 16 ; Syst. Antl., p. 96, 16; 

 Wiedemann, Dipt. Exot., I, p. 68, 2 ; Auss. Zw., I, p. 114, 3. — Macquart, Dipt. Exot., I, l,p. 142, 41 ; Bellardi, 

 Sagiiio, I, p. 58. — Harris, Ins. N. Engl., 3d Edit., p. 602. 



Tabanus niger Palisot-Beauvois, Ins., Dipt. Tab. I, f. 1. 



Tabnmis americanus Drury Ins., I, T.-dj. 44, f. .3. 



Tabamts validus Wiedemann, Auss. Zw., I, p. 113, 2. 



AFalc and female. Altogether black ; head of the male large, subhemispherical, the 

 large facets occupying an extended area, distinctly separated from that of the small facets; 

 front ( ? ) unusually broad ; callosity l>roader than long ; subcallus denuded, shining ; third 

 antennal joint deeply excised, its upper corner very salient, pointing forward, its narrow 

 portion remarkably long, gradually merging into the annulate tip ; front tibia3 whitish at 

 base, hind tibiaj with a fringe of black hair ; abdomen usually with a bluish white efflores- 

 cence ; wings black or brown ; first posterior cell strongly coarctate, often altogether closed. 

 Length, ordinary specimens, 20-2G mm. ; small ones down to 16 mm. 



Hah. United States, common. I have specimens from Quebec, Can., Maine, Massachu- 

 setts, where it is not rare (Cambridge, Nahant, Chelsea Beach), District of Coknnbia, Mary- 

 land, Indiana, Kentucky, Florida, Kansas, Nebraska, Texas. Bellardi had it from Mexico. 



