Genus: Test variable, chitinoid; binucleate (Illustrated Guide, 1985).
Species: Test 100-145 μm high, 100-152 μm in diam. (Cash, The British Freshwater Rhizopoda and Heliozoa vol. I, 1905).
Arcella mitrata Leidy, 1879: Test: brown, areolar, subspherical; diam. 100 - 200 μm; oral face diam. 65-100 μm; buccal depth 18-32 μm; height 115-165 μm; pseudostome lobed, waby, 25-90 μm. Similar species: A. jeanneli. Ref. Leidy (1879); Deflandre (1928). (Illustrated Guide, 1985).
Images of collecting locality:
No. 7, Mida-ga-hara (bog/marsh), Gassan (mountain), Tsuruoka city (formerly Haguro town) & Shonai town (formerly Tachikawa town), Yamagata Pref., Japan, August 3, 2006 by Y. Tsukii