"Genus Jakoba Patterson nom. nov.
Syn.: p.p. Cryptobia sensu Ruinen, 1938.

"Protists with two apically inserting flagella, one projecting forwards as a hook and adhesive, the second extending posteriorly with a ventral groove. Membrane of second flagellum expanded as a flattened vane for a short distance near its base. Three nonmicrotubular roots arising from the kinetosomes and giving rise to microtubules that support the walls of the groove. Mitochondrial cristae flattened. Phagotrophic, eating bacteria and other suspended particles. Forming cysts. One species: Jakoba libera (Ruinen, 1938) Patterson comb. nov.

"Cellulae solitariae, flagellis duobus disparibus apicaliter insertis, flagello antico unciformi adhaesivo, flagello postico in sulco ventrali corporis cellulae posito. Membranum flagelli postici prope basin flagelli per distantiam brevem dilatatum. Kinetosomata radicibus tribus ex microtubulis non constantibus instructa. Cristae mitochondriales complanatae. Cellular bacteria edunt et cystas verisimiliter faciunt. Genus monotypicum. Holotypus: Jakoba libera (Ruinen, 1938) Patterson, comb. nov.

"Basionym: Cryptobia libera (Ruinen, 1938)"

"The characters of the family are as follows: Biflagellated protists residing within a lorica and oriented with dorsal surface directed downward. Lorica of simple construction and not easily visible even using phase microscopy. Cells with two flagella, both of which have no mastigonemes. Membrane of the trailing flagellum modified as a flattened "wing-like" extension. Colorless organisms feeding upon bacteria. Engulfment of prey occurs in the ventral posterior half of the cell. Mitochondrial cristae tubular. Golgi apparatus absent or, if present, not prominent and comprised only of two to four cisternae.

"The life cycle consists of two stages: a highly motile aloricate dispersal stage and a loricate feeding stage. The aloricate dispersal stage swims actively with the anterior flagellum providing the propulsive force and the posterior flagellum acting as a rudder."

Typified name; type genus Histiona Voigt (1902, p. 33)