XIX. Prodrome of a Monograph of the Tabanid^e of the United States. 



Su2J2ilement. 

 By C. R. Osten Sacken. 



Read November 15, 1876. 



JoINCE the pviblication of the second part of this Prodrome, I have obtained some ma- 

 terials which enable me to complete and, in some respects, to correct, the descriptions of 

 the North American species of the genus Tabanus. 



To the fifty-four species already described by me, I add three, one of Say's species 

 {T. annulatus) which I did not possess before ; another, which I took at first for a possible 

 variety of Tah. abdominalis, and which I recognize now as a separate species {T. exul) ; 

 the thii'd seems to be new. The species which I brought from California I reserve for 

 another publication.^ I also give descriptions of the males of Tabanus fuscopunctatus 

 and rufus, which were not known before, and were recently obtained by Mr. H. K. Morri- 

 son ; and, finally, I complete the descriptions of T. lonrjus and Wiedemanni. 



A considerable proportion of my new material I owe to Mr. Geo. Dimmock, who collected 

 a large number of Tabani at Cumberland Gap, Kentucky, in July, 1876. The list of these 

 Tabani, with the number of specimens taken, is an interesting datum towards the knowl- 

 edge of the geographical distribution of the genus : — 1. T. longu,s, 50 specimens ; 

 2. atratus, common; 3. americanus, not rare; 4. /m?omZj(s, numerous specimens; 5. ab- 

 dominalis, 16 specimens ; 6. exid n. sp., 9 sp. ; 7. giganteus, 4 sp. ; 8. lineola, 6 sp. ; 

 9. melanoceriis, 2 sp. ; 10. molesius, 7 sp. ; 11. coffeatns, 6 sp. ; 12. costatus, 2 sp. ; 

 13. nigrescens, 3 sp. ; 14. Wiedemanni, 2 sp. ; 15. vivax, ? (?), 2 sp. ; 16. anmdatus, 1 sp. 



As the three species described here for the first time are not contained in the analytical 

 table of the species {ante p. 427), I prefix short diagnoses to the descriptions, in order to 

 facilitate their recognition. When the time comes to draw up a new analytical table of 

 the N. A. Tabani, it will be found more convenient, I think, to divide it in two parts ; one 

 for the Northern and Middle States, and a separate one for the Southern States. 



The name of my Tab. soclus (p. 467) must be changed, as there is an earlier T. socius 

 by Walker. I wiU call it T. epistates. 



Tabanus annulatus. 



Tabanus annulatus Say, Journ. Acad. Phil., Ill, 32, 2; Wiedemann, Auss. Zw., I, p. 185, 111. 



Female. Eyes glabrous ; frontal callosity unusually small ; thorax whitish pruinose ; 

 abdomen brown, hind margins of segments whitish pruinose and beset with white hairs ; 

 wings immaculate. Length, 12-13 mm. 



1 They are described ia the Bulletin of the U. S. Geological and Geographical Survey, Vol. 3, No. 2. 



(555) 



