Family HISTIOBALANTIIDAE de Puytorac & Corliss, n. fam.

Body elliptical in outline, with right side slightly concave and anterior end a little narrower than posterior; generally of large size; dense somatic ciliation, interspersed with longer bristles; prominent buccal caviry, medially located on ventral surface, containing distinctive tetrahymenal organization of buccal ciliary organelles plus scutico-vestige, though paroral membrane not prominent; two sizable macronuclei, with several micronuclei; commonly facultatively psammophilic forms, both fresh-water and marine habitats.

[Establishment of this family has been planned for some years by de Puytorac and me; Jankowski (1975), coincidentally, recently suggested the same familial name, but without characterization of the group.]

Histiobalantium Stokes, 1886 (syns. Histerobalantidium, Histiobalantidium, Histiobalantum). Few species.