Abstract
Some confusion exists as to the correct identity of Ostertagia trifurcata. The relevant literature is reviewed, and it is concluded that the observations of Sarwar (1954, 1956) pertaining to the identity of O. trifurcata are correct; that is that the genital cone possessed papillae. Teladorsagia davtiani is therefore a synonym of O. trifurcata and O. pinnata a valid species.