Genus: Highly flattened; pellicle firm; body form constant (Kudo, 1966).
Chloroplasts small, discoid, pyrenoids usually absent; most species flat and leaf-shaped;
often with ridges or fins running helically or longitudinally (Illustrated Guide, 1985).
Species: 45-100 μm long, 30-70 μm wide; short posterior prolongation slightly curved; a prominent ridge on the convex side; longitudinally striated; one ? circular paramylon (paramylum) body near center; flagellum as long as cell body (Kudo, 1966). Cell body nearly spherical at dorsal view; anterior end separated into two spherical projections; cauda strongly curved; dorsal ridge short or absent (cf. dorsal ridge present P. triqueter); cell body 40-80 μm long, 30-50 μm wide; two ? paramylon bodies disc-shaped; striae straight (An Illustrated Guide to Freshwater Zooplankton in Japan, 2000). |
50 μm
100 μm
150 μm; x 400 :
31 μm
63 μm
94 μm; x 640
