Genus: Preoral suture prominent; anterior suture extends to right immediately forward of oral area (Illustrated Guide, 1985). Ovo-cylindroid body, dark colored; no anterior cilia; transverse ring of long cilia near anterior end; cytostome small, near anterior ring of cilia; a long caudal cilium; common in decaying vegetation (How to know the protozoa, 1979). Ovoid to cylindrical; crescentic cytostome on slightly flattened area near anterior end; a zone of cilia around body; one (or more) long caudal cilium; cytoplasm yellowish to dark brown; macronucleus ovoid; a single contractile vacuole; fresh or brackish water (Kudo, 1966). Species: Cell body 50-65 μm long; nearly cylindrical; 15-16 ciliary rows; cytoplasm usually dark; fresh water among decaying vegetation (Kudo, 1966). Small, ovoid with a blunt anterior and rounded posterior; 50-65 μm long; transverse ciliary bands conspicuous; somatic ciliation uniform; the tuft of caudal cilia reduced (only one ?); spherical macronucleus; a single contractile vacuole central (Carey, 1992).

Loxocephalus plagius, cell body μm long, μm wide, x 400, x 640, Saitama Pref., May-June 1999 by Y. Tsukii
50 μm 100 μm 150 μm; x 400 : 31 μm 63 μm 94 μm; x 640

* Loxocephalus plagius (Stokes, 1885) Kahl, 1931 (Syn. Dexiotricha plagius Stokes, 1885): 50-65 μm long; nearly cylindrical; 15-16 ciliary rows; cytoplasm usually dark; fresh water among decaying vegetation (Kudo, 1966). Small, ovoid with a blunt anterior and rounded posterior; 50-65 μm long; transverse ciliary bands conspicuous; somatic ciliation uniform; the tuft of caudal cilia reduced (only one ?); spherical macronucleus; a single contractile vacuole central (Carey, 1992).

Loxocephalus intermedius Kahl, 1928: Elongate & cylindrical; 80 μm long; cytostome very small with reduced membranes; transverse ciliary bands from peristome to dorsal surface; somatic ciliation uniform with a tuft of caudal cilia; an ovoid macronuclei; a single contractile vacuole in the mid-body region (Carey, 1992).