Abstract
We investigated type material of Ulva montana (Lightfoot 1777: 973) and compared it with the type material of Gloeocapsa magma Brébisson in Brébisson & Godey (1835: 40) and fresh material from nature. Our investigation indicates a separate evolutionary lineage of U. montana which possesses specific morphological features differing from the most closely related genera Gloeocapsa, Gloeocapsopsis and Chroococcus. We propose a new genus Lightfootiella gen. nov. based on the new combination Lightfootiella montana comb. nov. We revise the taxonomy of this entity and compare this species with Gloeocapsopsis magma sensu (Brébisson) Komárek & Anagnostidis 1986.