Pyrgo williamsoni (Silvestri, 1923)
= Biloculina williamsoni, Silvestri, 1923
= Biloculinella elongata (Wiesner, 1923)
= P. elongata (d'Orbigny, 1826)
= Quinqueloculina elongata, Natland, 1938
= Spiroloculina elongata, d'Orbigny, 1839