Dodatak:Popis praživotinja, U

• Umbellasphaeridium S.M.Jardine et al.
• Unda Schaeffer, 1926
• Undulina E.R.Lankester
• Unellium R.Rauscher
• Urceolopsis A.C.Stokes
• Urceolus C.von Mereschkowsky, 1879
• Urinympha L.R.Cleveland, Hall, E.P.Sanders & Collier