TWO CRETACEOUSSTELLARIMASPECIES:S. STEINYIANDS. DISTINCTA; THEIR MORPHOLOGY, PALAEOGEOGRAPHY AND PHYLOGENY

Abstract
Stellarima steinyi (Hanna) Hasle & Sims, both in its resting spore stage and its presumed vegetative stage, is described from the late Cretaceous deposits of the U.S.S.R., the Alpha Ridge in the Arctic Ocean, and California, U.S.A. Stellarima distincta (Long, Fuge & Smith) Hasle & Sims is described from the late Cretaceous of California and comparisons are made with S. steinyi and briefly with the two living Stellarima species, S. microtrias (Ehrenb.) Hasle & Sims and S.slellaris (Roper) Hasle & Sims. Possible palaeoceanographic and evolutionary sequences are discussed.