NEIDIUM PALPEBRUM SP. NOV., A NEW DIATOM FROM FLORIDA (U.S.A.): COMPARISON WITH N. SACOENSE REIMER, AND SOME REMARKS ON BIOGEOGRAPHY

Abstract

In modern samples from lakes in Florida's Ocala National Forest, U.S.A., a new species, Neidium palpebrum sp. nov. was described. This diatom possesses lanceolate valves with protracted, broadly rounded apices and a single, large, rugose longitudinal canal along each valve margin. The new species is also characterized by an elliptical central area, external proximal raphe ends deflected in opposite directions, areolae organized into regular rows, the valve face/mantle junction sharply delineated, and a relatively deep mantle. Neidium palpebrum is a larger diatom that shares some similarities with N. sacoense. The relationship of these two species is discussed, based on morphological features observed with light and scanning electron microscopy. Some remarks on the biogeography of these two Neidium species are included.