Matsakision Bonnet, 1967
Diagnosis: Shell hyaline, elongated ovoid, very little compressed, truncated perpendicularly or very slightly obliquely in the region of the pseudostome. Pseudostome acrostome or very slightly plagiostome, sub-circular, with a slight neck, which can sometimes be barely noticeable. Shell covered with elliptical scales, sub-circular near the pseudostome, without very clear orientation, not overlapping, although sometimes they may be contiguous, and embedded in a light yellow hyaline cement.
Type species: Matsakision cassagnaui Bonnet, 1967
Type location: Vityna Pass, Peloponnese, Greech. At 1000 m altitude, in sloping fir forest; powdery soil brought in by wind, at the base of mosses and of the fern Asplenium adiantum-nigrum, on limestone rock in the undergrowth.
Remarks: Bonnet (1967) did not observe living cells, but based on the general constitution of the shell he believed that this genus belonged to the Filosea. Matsakision can be distinguished from:
– Corythion, by its extremely weak plagiostomy and by the pseudostome in the neck without invagination.
– Cyphoderia, by the elliptical shape of the scales and by their completely different arrangement.
– Cyphoderiopsis, by the fact that, in this last genus, the scales are circular and of variable size.