Local and intercontinental comparisons of test morphology in the little-known testate amoeba Cyphoderia laevis Penard

The morphology of tests (“shells”) representing populations of the small testate amoeba Cyphoderia laevis Penard, 1902 (Cercozoa, Euglyphida) from Canada and Hungary was quantified. Despite often considerable variation the cross-sectional shape of tests, multivariate statistical analysis confirmed the general uniformity of test morphology within populations and between populations at both local (regional, inter- and intra-watershed) scales and over inter-continental scales (Canada and Hungary). Corrections are suggested to recently published misidentifications of C. laevis as Corythionella georgiana Nicholls. The differences between these two taxa are subtle, but significant, and are emphasized here to help preclude similar errors in the future. Schaudinnula nana Badewitz, 2003 is shown to be a superfluous synonym for Cyphoderia laevis. Cyphoderia truncata Schulze, 1875 has some similarities to C. laevis, but its status remains unresolved. Some preliminary reservations are expressed about the classification of Cyphoderia laevis within the genus Cyphoderia owing mainly to its Corythionella-like scale structure and other characteristics of its test that appear to be outside the “usual” range found in other Cyphoderia species.