Description of Dinema australiense:
Ciliate, 45-65 x 20-25 microns, laterally slightly flattened, ventral view fusiform with both ends rounded. Macronucleus slightly ellipsoid, usually close above centre of cell opposite buccal cavity, contains some comparatively large nucleoli sometimes connected by narrow bridges. Micronucleus slightly ellipsoid, in indentation of macronucleus. Contractile vacuole in mid-body, with single excretory pore underneath buccal cavity. Cytopyge in median of cell between excretory pore of contractile vacuole and posterior end of cell. Cortex thick, glassy, distinctly furrowed by ciliary rows, especially preorally. Extrusomes (trichocysts) 5-7 microns long conspicuous, fusiform, obliquely attached to pellicle and close to somatic basal bodies; extruded trichocysts up to 35 microns long, needle-shaped. Cytoplasm colourless, with many food vacuoles often containing only few bacteria and/or food residues. Swims slowly and crawls on soil panicles. Somatic kineties with (on avergage 18) long and rather stiff cilia, single throughout, rarely does a dikinetid occur at anterior end of postoral kineties. Distances of kinetids increase within kineties from anterior to posterior, those in first kinety right of oral apparatus so closely spaced in upper portion that they are easily mistaken for the paroral membrane. Ciliary rows bipolar on dorsal side, those on ventral surface form short but wide preoral suture, because anterior left kineties abut obliquely on anterior right kineties which gradually shorten from anterior end of cell to oral apparatus. Four postoral ciliary rows, first kinety commences left of distal end of paroral membrane, other kineties originate slightly unden1eath adoral organelles. No elongated caudal cilia. Oral apparatus in second quarter of cell, with conspicuous cone-shaped buccal cavity containing 1 large and 2 small adoral organelle. Adoral organelle l is very near distal end of paroral membrane and is tiny being composed of 2-4 cilia only; organelle 2 likewise small, being composed of 2-3 rows with about 4 cilia each, near posterior vertex of buccal cavity close above organelle 3, which is comparatively large and composed of 3 rows with about 6 cilia each. Paroral membrane composed of 32 dikinetids on average, curved loop-like along right, upper and left margin of buccal cavity, composed of distinctly inclined dikinetids having only anterior basal bodies ciliated. Cytopharyngeal basket large but very delicate, thus not recognizable in living cells; commences in upper buccal cavity and extends as wide tube near to anterior end of cell, where it curves dorsally and posteriorly.