Microchlamys patella

Testate amoeba, the lorica is usually circular when seen from 'above', and from side-view like a shallow convex inverted saucer, between 31-48 microns in diameter and 13-16 microns deep. A small skirt is often seen at the shell margin which appears to be uneven and possibly flexible. The surface of the text can be smooth or have an uneven bumpy structure, with some indication of a regular pattern. The skirt usually has a patterned surface even if the general body of the shell is smooth. Empty shells viewed from underneath have a more distinct pattern, suggesting that the inner surface of the shell is probably thinner than the outer. The whole shell may be transparent, light yellow or brown, although brown shells often have a margin which is less dense in colour even if the shells are empty. The general assumption is that colour is dependant on age, lighter shells being from more short-lived organisms.

Colpodid ciliate, length 35-130 microns. Oval, right body margin (dorsal side) distinctly convex, left (ventral side) slightly concave at level of oral apparatus. Well-nourished specimens almost unflattened, starving individuals very flat and anteriorly conchoidally depressed. Macronucleus spherical to slightly ellipsoid, usually in mid-body left of median, just underneath cytostome; nucleolus lobed, distributed in clod-like structures at periphery, or as indistinct mass in centre of macronucleus. Micronucleus not known. Contractile vacuole at posterior end, without collecting canals; single left lateral excretory pore (diameter 3-4 microns) slightly subterminal and exactly in median of cell. Cytoplasm with strong cyclosis, many 1-2 microns sized yellowish droplets, well-nourished specimens are crammed with food vacuoles 8-12 microns in size. Feeds mainly on algae and small ciliates. Movement is a slow gliding. Somatic and oral Infraciliature similar to Hausmanniella discoidea but lacking polymerized patch at right side. 50-100 dikinetids in 4th somatic kinety right of oral apparatus. About 10 successively shortened vestibular kineties on slope and inner side of right vestibular wall. Vestibulum, even that of microstomes, larger than in Hausmanniella discoidea, distinctly funnel-shaped in macrostomes. Left oral polykinetid 20-28 microns long, crescentic, proximal half covered by right wall of vestibulum, distal portion exposed on surface of cell.

See Microchlamys patella