Family: Test rigid, chitinoid, often areolar, smooth; pseudostome ventral, round
(Illustrated Guide, 1985).
Genus: Test variable, chitinoid; binucleate (Illustrated Guide, 1985).
50 μm
100 μm
150 μm; x 400 :
31 μm
63 μm
94 μm; x 640
Arcella, x 400, x 640, Uruguay Nov. 1999, photo by Yuuji Tsukii
