Testate amoebae

Testate amoebae (thecamoebians, formally Testacea or Thecamoeba) are a polyphyletic group of ameboid protists characterized by the presence of a test. Testate amoebae mainly include the filose Euglyphida (Rhizaria: Cercozoa) and the lobose Arcellinida (Amoebozoa), but also some minor groups like the filose Amphitremida (Stramenopiles: Labyrinthulomycetes) and Tectofilosida (Rhizaria), and the lobose Cochliopodium and Trichosida (both in Amoebozoa).

Traditionally, those species that form large networks of anastomosing pseudopodia, despite of some of them having tests, are not counted amongst testate amoebae; this comprises genus Gromia and the Foraminifera (both in Rhizaria).

The Thecamoebida (Amoebozoa), with the genus Thecamoeba, despite their name, do not have tests.

Testate amoebae taxa are differentiated by their test characteristics and the type of pseudopodia (lobose or filose). Testate lobose amoebae (Testacealobosia) produce wide pseudopodia while testate filose amoebae (Testaceafilosia) produce slender pseudopods.

Testate amoebae are closely related to the Foraminifera.

...
Wikipedia