Microchlamys sylvatica Golemansky et al, 1987


Diagnosis: Shell semitransparent, yellow brownish, with a darker central part, older specimens are brown; in dorsal view the shell is usually circular. In live specimens the shell is sometimes folded underneath and has a cocoon-like appearance. The shell form of live specimens resembles a plate in its lateral view with a slightly convex ventral part. Empty shells have a flat ventral side. Shell structure is similar to that of M. patella according to the description of Penard (1902) and Ogden (1985). Dorsal surface punctuation can be distinguished better in the central part of the shell, while in its light peripheral margin the sculpture is fine and the shell appears smooth. A thin, non-structural, flexible and transparent membrane is observed on the ventral side of the shell. The pseudostome with an uneven circular form is situated medianly, size approximate 1/3 of the shell.The cytoplasm of living animals occupies the central part of the shell in a spherical pattern. Epipodia were not observed. Lobopodia are clearly distinghuished when the shell is folded on its ventral side. Pseudopodia were not observed in specimens stick- ed to the substrate. The nucleus is of a vesicular type, deficient of chromatin.
Shallow pits, c. 0.6 µm in diameter, are scattered throughout the dorsal surface, which is covered by a filamentous coat. Pores perforating this coat are evident in some pits. A layer of middle electron dense material without discernible structure is located underneath the surface coat. The middle part of the test consists of a continuous system of electron-trans­lucent cavities and this system directly communicates with the outer medium via the surface coat pores. The ventral side is also covered by the filamentous coat, but its underneath layer differs from the underneath layer of the dorsal side. The cytoplasm is surrounded by a plasma membrane with a thin glycocalyx-like structure on its surface and a dense layer of parallel fibrils underlying it. Numerous spherical granules with alveoli inside them appear in the cytoplasm, most probably representing calgenous granules (all from Golemansky, 1987)


Dimensions: diameter of shell: 140-175 µm, mean 160 µm (n=113).


Ecology: brown forest soils, Bulgaria