454 C. R. OSTEN SACKEN'S PRODROME 



by the white color of the base of the front tibiaj, the bhickish or brownish, and not ferru- 

 ginous brownish, wings, the absence of clLstinct white hues on the thorax, etc. The head 

 of the male is much larger than in T. ni(/rescens, and the large facets occupy much more 

 surface. 



30. Tab anus stygius. 



Tabanus stygius Say, Jouni. Aead. Phil., Ill, p. 33, 3; Wiedemann, Auss. Z\v., I, p. 131, 31. 



Female. Frontal callosity much longer than l>roa/l, chestnut brown, with a spindle- 

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

 brown ; palpi black ; antennre 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 Avith a white pollen, through which the brown ground 

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

 cence makes the 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 tibije 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. 



Hah. Connecticut (Southington, July, W. H. Patten); Pennsylvania; Marj'land 

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

 South Carolina (Sea Islands, June 2d, B. P. Mann) ; 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) ai'e dark green with two dark pur- 

 plish bands and the vestige of a thiixl above ; therefore similar to the eyes of T. nigrescens. 



31. Tabanus atratus. 



Tahcmus atrahis Falmciup, Syst. Entom., p. 789,9; Entom. Syst., lY, p. 3GG, 16 ; Syst. Antl., p. 96, 16; 

 Wieileniann, Di]it. Plxot., I, p. 63, 2 ; Auss. Z\v., I, p. 114, 3.— Macquart, Dipt. Exot., I, 1, p. 142, 41 ; Bellardi, 

 Saggio, I, p. 58. — Harris, Ins. N. Engl., od Edit., p. 602. 



Tabanus niger Palisot-Bfauvois, Ins., Di]it. Tab. I, f. 1. 



Tahmms anicricam/s Drury Ins., I, T;d>. 44, f. 3. 



Tabanus valk/i(s Wiodoniann, Auss. Z\v., I, p. 113, 2. 



3fah 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 broader than long; subcallus denuded, shining; third 

 antennal joint deej^ly excised, its upper corner very salient, pointing forward, its narrow 

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

 base, hind tibia) 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 nun. ; small ones down to 16 mm. 



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

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

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



