Microworld

world of amoeboid organisms

Menu
Quadrulella alata
Q. alata, after Gauthier-Lièvre, 1957

Quadrulella alata  Gauthier-Lièvre, 1957

Diagnosis: In frontal view, the test is lageniform, with a broadly rounded fundus (subcircular or ovoid) and a wide neck forming about a third of the total height; pseudostome slightly arched and bordered by a very thin chitinoid lip. Test with a flat but probably not hollow keel which surrounds the test towards the base of the collar. Test highly compressed in lateral view, claviform with ogival base terminated by a sharp nipple or foam; pseudostome slightly indented. Apical (or basal) elongated ellipsoid view with, at each end of the ellipse, the more or less acute projection of the keel.
Test colorless or yellowish, very hyaline; covered with fairly large square plates, regularly arranged, juxtaposed or more or less overlapping. The keel is formed by two series (one for each side) of rectangular plates; on top of the fundus some thin plates are inserted in these rows giving in lateral view the appearance of a truncated nipple and not of an acute keel as in apical view. The insertion of the plates forming the keel is often marked by a bead of chitinoid cement.

Dimensions: Length 140-150 µm; width 70-90 µm ; thickness 48-50 µm; collar 15-55 µm high and 33-35 µm wide; pseudostome 30 µm; keel 5-10 µm wide.

Ecology: Freshwater. Marshy stream on Kalahari sands. Rep. of Congo: stream between Ewo and Etoumbi (about 25 km. From Ewo), quite rare, October.

Recent posts

Kibisidytes

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 »

Phaeobola

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 »