204 PROC. ENT. SOC. WASH., VOL. 20, NO. 9, DEC., 1918 



T. nigrovittatus Macquart. Maryland near Plummers Island, 

 July 11, 1909 and July 27, 1916; McAtee; Falls Church, Va., 

 female on flowers of chinquapin, June 29, Nathan Banks; Four- 

 mile Run, Va., male, May 31, 1914; McAtee. Said to be distinct 

 from costalis in the maritime part of its range; here it is but 

 feebly differentiated. 



T. pumilus Macquart. Very abundant; extreme dates of col- 

 lection May 30 and August 21; males taken July 2 and 6. 

 Hovers about the head like a Chrysops. (P. I.) 



T. recedens Walker. Branchville to Beltsville, Mel., June 4, 

 1914, McAtee; Beltsville, Md., June 23, 1917, C. T. Greene. 



T. reinwardtii Wiedemann. Maryland near Plummers Island, 

 July 27, 1916, McAtee; a very neatly colored species. 



T. sagax Osten Sacken. Beltsville, Md., June 18 and August 

 6, 1916; Maryland near Plummers Island, July 27, McAtee. 



T. sparus Whitney. Beltsville, Md., June 18, 1916, McAtee, 

 identified by Jas. S. Hine; Maryland near Plummers Island, June 

 29, 1913, J. D. Hood; Eastern Branch, D. C., May 30, H. S. 

 Barber. 



T. sulcifrons Macquart. Abundant, extreme dates of col- 

 lection June 28 and October 1; males taken July 6, 7, 13, 20, 26 

 and August 10, 20, and 26. (P. I.) 



Osten Sacken predicated T. abdominalis upon specimens with 

 closed first posterior cell. 4 This is an adventitious character and 

 due to giving it great weight, his conception of the species prob- 

 ably is faulty. Apparently we have two species or perhaps sub- 

 species of this group, separable on the relative extent of the coarse 

 and fine facets of the eyes of the males. Neither original de- 

 scription of abdominalis or sulcifrons mentions the males. The 

 descriptions of the females are so alike that it is little wonder 

 Osten Sacken seized avidly on the supposedly definite character 

 of closed cell (which was mentioned only incidentally by another 

 than the original describer.) 



It seems wise, however, for the reason mentioned above, to 

 place no reliance on this character. This procedure renders the 

 name exul 0. S. unnecessary. Since there is no appreciable 

 difference in the original descriptions of abdominalis and sulci- 

 frons, it seems base to base these forms on the character of the 

 eyes in the males as pointed out by Osten Sacken. In T. sulci- 

 frons the dividing line between the fine and coarse facets of the 

 eyes lies much higher than in T. abdominalis, at about the middle 

 of the height of the head. The portion of the eye below the line 



4 Osten, Sacken, C. R. Prodrome of a Monograph of the Tabanidae 

 of the United States. Part II, The genus Tabanus. Mem. Bost. Soc. 

 Nat. Hist. II, pp. 434-436, 1876. 



