world of amoeboid organisms

Corythionella georgiana, after Nicholls, 2005

Corythionella georgiana Nicholls, 2005

Diagnosis: Shell translucent, colourless to pale yellow in colour, elongate-elliptical to nearly circular in outline (ventral and dorsal views). Shell with a rounded-triangular outline in optical cross-section. Pseudostomal aperture separated from the main body of the shell by a short bent neck having a slightly flared anterior rim (not readily observed in some specimens). Test covered with small (0.7-0.9 × 1-2.3 μm) elongated silica scales, randomly arranged with no overlapping of their margins. Protoplast with long, sometimes branching filose pseudopodia.

Dimensions: Length 33-(39)-41 µm , width 21-(24.5)-27 µm, height 17-(18)-20 µm (n=63).

Ecology and distribution: Freshwater. Beach sand in the wave zone (supralittoral) at Beach Number 2, Wasaga Beach, Georgian Bay, Lake Huron. Ontario, Canada (44° 29′ 18″ N; 80° 04′ 17″ W).

Recent posts


K. marinus, after Jepps, 1934 Kibisidytes marinus Jepps, 1934 Diagnosis: Small amoeboid organism occurring in the sea, attached to the surface film or to some

Read More »


P. aeris from Dumack et al., 2000 Phaeobola Dumack et al., 2000 Diagnosis: Cells roundish to oval shaped. Shell colorless to amber-colored, rough surface, few

Read More »

Rhizaspis armata

R. armata, 68 µm long, excl. spines – Laegieskamp Rhizaspis armata (Lauterborn, 1901) Dumack et al., 2021 Basionym: Pamphagus armatum Lauterborn, 1890 Diagnosis: Theca membranous,

Read More »

Rhizaspis spinosa

The original description with original drawings, Penard, 1890. Rhizaspis spinosa (Penard, 1890) Dumack et al., 2021 Basionym: Trinema spinosum Penard, 1890 Diagnosis: Theca membranous, ovoid

Read More »

Difflugia “pseudoclaviformis”

Difflugia “pseudoclaviformis”, front and side view, 424 µm Difflugia “pseudoclaviformis” Diagnosis: Shell pyriform, compressed, with a more or less pronounced aboral protuberance; shell composed of

Read More »

Difflugia from Lolo Pass

Shells 461-448 µm, stacked image. I found this large en remarkable shells in sediment of a small mountain lake near Lolo Pass, Montana USA. It differs

Read More »

Foraminifer drome

Unknown species, collected from the river Drôme, France, 2021 Unknown species September 2021, I found about ten specimens of an agglutinated foraminifer in a sample

Read More »

Cyclopyxis spec

Cyclopyxis spec., 168 µm Cyclopyxis spec. Diagnosis: Shell circular in ventral and dorsal view, more or less hemispherical in lateral view (height/diameter ≈ 0.5); lateral

Read More »

Difflugia fallax

Difflugia fallax, from Penard, 1902 Difflugia fallax Penard, 1890 Diagnosis: Shell hyaline or yellowish-greenish, black at low magnification, round in cross section, formed of a

Read More »