cf Luffisphaera spec.
I found some cells in a sample from the Bert Bospad. They were moving slowly, but without rolling locomotion. The cells were half domed, with some short filopodia visible(see below). A number of tubular elements or ‘spines’ cover the cell. At the base of these spines smaller elements are visible. The top of each spine widens a little. The spines are hollow (see image below). It could be a Luffisphaera species, and if so, it resembles L. cucumiformis, though that species is much smaller.
Cell diameter: c. 5-9 µm; length of tubular spines 2.6-6.1 µm; width of spines 0.6-0.8 µm