LAUSR

The genus Luticola is characterized mainly by valves with an internal longitudinal channel located at the valve face/mantle junction, rounded areolae and an isolated pore (stigma) near the central area. Studies on Luticola species that occur in Brazil are scarce. Therefore, this paper illustrates and describes the morphology of 18 species of Luticola under optical and scanning electron microscopy, from 15 rheophilic environments of an Atlantic Forest in southern Brazil. Two new species are proposed: Luticola moreirae Straube, Tremarin et T. Ludwig and Luticola papilioformis Straube, Tremarin et T. Ludwig, and are compared with morphologically similar species. Furthermore, the ultrastructure of Luticola camopiensis is revealed and described from SEM. Luticola beyensii, L. camopiensis and Luticola saprophila are recorded for the first time from Brazil.