Holotricha

[1] The order Holotricha was erected in 1859 by Friedrich Stein, who developed a system of classification in which ciliates were categorized according to the type and distribution of their cilia.

[6] Versions of Bütschli's two-order scheme were used by taxonomists throughout the first half of the twentieth century, although many adjustments were made to the arrangement of families and genera within those groups.

[7][8][9] Meanwhile, improved laboratory methods and the advent of the electron microscope began to reveal inadequacies in the old scheme; and, as inconsistencies accumulated, dissatisfaction with the system grew.

[10] Nonetheless, Holotricha remained in use as a high-level taxon until 1974, when John Corliss proposed a complete revision of the phylum Ciliophora.

Recent systems of classification, including an influential scheme proposed by Pierre de Puytorac in 1994, and Denis Lynn's revision of 2002, make no mention of Holotricha.