Microworld

world of amoeboid organisms

Menu

Aperture usually surrounded by pores. Aperture diameter 0.45 of shell diameter. Shell diameter 70-160 µm.

Aperture surrounded by pores. Aperture diameter ≥ 0.4 of shell diameter. Shell very flat; diameter 140-402 µm.

Aperture surrounded by pores. Distinct basal rim. Height ca 1/3 of shell diameter.

Shell elliptical, quadrate or circular. Shell often with distinct dorsal folds or ribs. Aperture small and with pores.       

A. conica

Shell with six or more ribs; dorsal surface with ribs and depressions; aperture smooth, without crenulations.

Arcella n. sp.
Shell with flattened top and aperture with crenulated border; usually with six ribs.
A. costata

Shell in side view trapezoid, with six or more ribs; aperture smooth without crenulations.

 

Shell in lateral view trapezoid, with 5-7 ribs. Aperture with pores.

A. intermedia

Shell with basal border. Dorsal surface with depressions. Diameter c. 80-110 µm.

Arcella

Shell with basal border. Dorsal surface with depressions. Diameter c. 80 µm. 

Arcella

Shell in lateral view hemispherical, with acute or somewhat rounded corners,  sometimes with a basal border. Diameter c. 35-55 µm. 

A. hemisphaerica

Shell hemispherical, with smooth and broad rounded corners in lateral view. 

Arcella
Arcella

Shell with distinct basal border. Ratio diameter aperture/shell 0.2.

Arcella crenulata
A. crenulata
Arcella crenulata

Shell dome shaped; aperture with irregular crenulated border.       

Arcella excavata
A. excavata

Shell formed like a saddle. Aperture elliptical.       

Shell balloon shaped.       

Test broader than high; height c. 80-90 µm.  

Shell with undulations, more or less spherical. 

Shell spherical, wrinkled.       
A. rukiensis

 

Shell shaped like an old hat.

Arcella formosa

Shell resembling a pie; prominent folds or ribs often with darker color.       

Arcella brasiliensis
Arcella

Shell with striated border

Arcella

Shell with a number of projections.

Arcella

Shell border with numerous small spines.

Arcella multilobata

 

Shell flattened, with crenulated aperture.

A. corona

 

Shell crowned with some spines.

 

Shell with high dome and distinct neck.

Arcella gandalfi

 

Shell like Gandalf’s hat.

 

Shell sub-hemispherical, round smooth aperture, thickened edges

Recent posts

Pelomyxa video

Pelomyxa palustris Pelomyxa palustris, found below decaying leaves in the hollow of a beech Pelomyxa palustris, found below decaying leaves in the hollow of a

Read More »

Hoogenraadia galeata

H. galeata – from Stepanek, 1963 Hoogenraadia galeata  (Stepanek, 1963) n. comb. Gillardella galeata Stepanek, 1963 Diagnosis: Shell somewhat similar to the shell of Corythion dubium

Read More »

Arcella grospietschi

Arcella grospietschi, after Stepanek, 1963 Arcella grospietschi  Stepanek, 1963 Diagnosis: Shell disc-shaped, yellow-brown, in ventral view with a undulated border, with seven large and seven smaller

Read More »

Arcella oyei

Arcella oyei, after Stepanek, 1963 Arcella oyei  Stepanek, 1963 Diagnosis: In dorsal view, the shell is circular, with 10 apparent broken lobes on the surface. In

Read More »

Centropyxis halophila

C. halophila, after Bonnet, 1959 Centropyxis halophila Bonnet, 1959 Diagnosis: Shell with ovoid sole, extended by a rather strongly covering visor and not clearly separated

Read More »

Euglypha cuspidata

Euglypha cuspidata Euglypha cuspidata  Bonnet, 1959 Diagnosis: Shell small, very transparent, ovoid, in lateral view very elliptical, with sharp edges. Pseudostome small, elliptical, surrounded by a

Read More »