Genus: Test variable, chitinoid; binucleate (Illustrated Guide, 1985).
Species: 30-70 μm diam.,
25-40 μm high;
pseudostome round, 10-20 μm,
invaginated 8-10 μm, short inverted rim;
test finely areolar, yellow to brown (Illustrated Guide, 1985).
Arcella hemisphaerica (or Centropyxis sp. ?),
test 66 μm diam., 25 μm high, pseudostome 25 μm diam.
more or less anterior, test not chitinoid ?,
x 400, Japan, 199? by Y. Tsukii
50 μm
100 μm
150 μm; x 400