Rhogostoma (row-gaw-stow-ma) is a rarely reported amoeba with a flexible surrounding test and with a small opening through which pseudopodia can emerge. Cluster of cells with common cytoplasm, at the centre of the cluster. Phase contrast.
Pseudodifflugia, a testate filose amoeba. These are small species with a chitinoid ovoid or spherical test covered with quartz particles. Difflugia are generally larger and have lobose pseudopodia. Pseudodifflugia feeds on diatoms and other algae. From freshwater koi pond near Boise, Idaho. Phase contrast.