Rhogostoma spec.

Diagnosis: Shell spherical, covered with small mineral grains; aperture is a small rectangular slit, invaginated; pseudopodia small digitate, usually extending from a broad lamellipodium.

Dimensions: Shell c. 35 µm (n=20)

Habitat: Sediments of peatbog, the Netherlands.

Remarks: This amoeba came up in a wet mount kept for several days in a moisture chamber. The test is broadly ovoid and covered with small xenosomes. The pseudostome is a small slit, shaped as a rectangular hole. This pseudostome is perpendicular to the longitudinal axis of movement. The amoeba moves by means of a broad hyaline veil, with an irregular border on which small digipodia appear. The uroid is formed by some trailing filaments, which can be branched. No nucleus could be observed. About twenty cells were present in the mount. The sample came from the Bert Bospad. One week later I found a specimen in a sample from the Dammerkade, also in the Netherlands. Recently I found it in samples from Crailoo.
The veil is extremely thin and hard to detect in normal light. That could be the reason that this remarkable amoeba has been overlooked in the past.
This could also be a Capsellina species.