Family: With 2 or more frontoventral cirral files parallel to long axis of ora region along its right border; at least 2 frontoventral files extend almost length of body (Illustrated Guide, 1985).
Genus: Cirral files not extend backward as far as transverse group (Illustrated Guide, 1985). Rsembles Oxytricha; but with three frontal, 2 rows of ventral, 4 caudal (transverse ?) cirri; longer adoral zone (How to know the protozoa, 1979).

Gonostomum sp. 4 clips Higashi-hiroshima Hiroshima, 1998