world of amoeboid organisms


Key to Euglypha species

1 Fundus with a tuft of spines (Fig. 1) 2
Fundus without spines or when present spines not in a tuft 4
2 Fundus with 1-2 spines, shell 100-140 µm (Fig. 1e) E. mucronata
Fundus with a tuft of 1-8 spines, shell < 80 µm 3
3 Shell with somewhat concave sides (Fig. 1a-c) E. cristata
Shell ovoid, slightly compressed (Fig. 1d) E. bryophila

Fig. 1: a-c E. cristata b var. major d E. bryophila e E. mucronata

4 Shell usually with spines 5
Shell without spines 10
5 Spines are elongated tapering body scales 6
Spines are not part of body scales 9
6 Spines much longer than the scales 7
Spines about as long as the scales 9
7 Shell more or less broad ovoid, almost spherical E. cabrolae
Shell elongated ovoid 8
8 Shell with few long spines near the aperture (Fig. 2a) E. brachiata
Shell with some long spines near the fundus (Fig. 2c) E. acanthophora
9 Mid-body region with some randomly distributed pointed body plates. E. dickensii
Fundus region with sharply pointed body plates E. penardi

Fig. 2: a E. brachiata b E. scutigera c E. acanthophora d-e E. tuberculata

10 Shell ovoid, in cross-section circular 11
Shell ovoid or pyriform, in cross-section more or less compressed 13
11 Shell small, < 30 µm E. laevis
Shell > 50 µm 12
12 Scales oval (Fig. 2e) E. tuberculata
Scales pointed, scutiform (Fig. 2b) E. scutigera
13 Shell ovoid, slightly compressed, without spines (Fig. 3e-f) E. rotunda
Shell oviform or pyroid, usually with spines 14
14 Spines long 15
Spines short 16
15 Spines like needles, limited to the edge of the shell E. filifera
Spines usually lanceolate, but not always clearly visible; spines limited to the edge and the posterior end of the shell. E. compressa

Fig. 3: ad E. strigosa c var. glabra ef E. rotunda


16 Spines usually numerous, distributed all over the shell surface; Apertural scales clearly larger than the shell scales, about twice as wide; aperture usually round or slightly oval E. ciliata
Spines usually short and numerous, distributed all over the shell surface; Apertural scales about the same size as the shell scales E. strigosa
Key based on Hoogenraad en de Groot, 1940, and Edward Mitchell, 2003
Recent posts


M. ovalistoma – after Bartos, 1963 Metaheleopera  Bartos, 1963 Diagnosis: Shell clearly narrowing towards the pseudostome, which can be seen even more clearly on the narrower sides

Read More »

Matsakision radixicola

M. radixicola – after Chardez, 1974 Matsakision radixicola  Chardez, 1974 Diagnosis: Shell ovoid, slightly compressed, transparent; pseudostome oval, truncated perpendicularly, with a slight neck. Shell

Read More »

Matsakision cassagnaui

M. cassagnaui – after Bonnet, 1967 Matsakision cassagnaui  Bonnet, 1967 Diagnosis: Shell hyaline, elongated ovoid, very little compressed, truncated perpendicularly or very slightly obliquely in

Read More »


Matsakision – after Bonnet, 1967 Matsakision   Bonnet, 1967 Diagnosis: Shell hyaline, elongated ovoid, very little compressed, truncated perpendicularly or very slightly obliquely in the region

Read More »

Arcella marginata

Arcella marginata, after Deflandre, 1929 Arcella marginata Daday, 1905 Diagnosis: Shell roughly hemispherical, rather overhanging, with a flattened, smooth edge. In dorsal view showing a

Read More »

Arcella lobostoma

Arcella lobostoma, after Deflandre, 1929 Arcella lobostoma Deflandre, 1929 Diagnosis: Shell hemispherical. In ventral view, irregular circular outline, often a little elliptical; pseudostome irregularly lobed:

Read More »