Genus: Cell body small, length = width, strong constriction at its center; semicells inverted triangular, ellipsoidal, rectangular, etc. in shape; straight or slightly curved spiny projections at each corner; one pyrenoid in each semicell; cell wall smooth (Illustrations of The Japanese Fresh-water Algae, 1977).
Species:
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A. octocornis
21 x 17 μm
Iroha-numa
Zao mountain
Yamagata, 2005
A. octocornis
μm
Kannon-numa
Shimogo
Fukushima, 2008
A. octocornis
μm
Omine-numa 5
Minakami
Gunma, 2007
A. octocornis
31 x 24 μm
29 x 26 μm
Kumakubo
Nasu-shiobara
Tochigi, 2005
A. octocornis
μm
Kareki-numa m.
Nikko
Tochigi, 2008.9
A. octocornis
35 x 35 μm
Kashibaru marsh
Karatsu
Saga, 2006