Typification and reassessment of seventeen species of coralline red algae (Corallinales and Sporolithales, Rhodophyta) described by W. Ishijima during 1954–1978

Abstract

Type specimens of 17 species of non-geniculate coralline red algae belonging to the Corallinales and Sporolithales (Corallinophycidae, Rhodophyta) and established between 1954 and 1978 by Wataru Ishijima have been re-examined, focusing on characters relevant to modern coralline taxonomy. The species are from the Early Cretaceous, Eocene, Oligocene, Miocene and Pleistocene rocks of southern and central Japan, Indonesia, Malaysia, Indian Ocean, Philippines, Pakistan and the Galapagos Archipelago, and were attributed by Ishijima to Lithothamnion (as Lithothamnium), Mesophyllum, Lithophyllum and Archaeolithothamnion (as Archaeolithothamnium). With two exceptions, all species are reassigned to different genera or are of uncertain generic placement within particular subfamilies, families or orders. The type specimen of Lithophyllum oboraensis is retained in Lithophyllum and the type specimen of Mesophyllum izuensis is retained in Mesophyllum. The type specimens of Lithophyllum izuensis (Ishijima) comb nov. (= Lithothamnion izuensis), Phymatolithon tokumanensis (Ishijima) comb. nov. (= Mesophyllum tokumanensis), Sporolithon borneoensis (Ishijima) comb. nov. (= Archaeolithothamnium borneoense) and Sporolithon galapagosensis (Ishijima) comb. nov. (= Archaeolithothamnion galapagosensis) possess features justifying their assignment to various genera within a particular family and subfamily. A specimen ascribed by Ishijima to Archaeolithothamnion galapagosensis (as Archaeolithothamnium) in the protologue of that species is a misidentified specimen of Sporolithon ptychoides Heydrich. The type specimens of Lithophyllum minoensis and Mesophyllum indicum belong to the Corallinaceae, subfamily Mastophoroideae but are of uncertain generic placement. The type specimens of Lithothamnion makinogoensis, L. nodai, L. tenuicrustatum, Mesophyllum niinoi and M. yuyashimaensis belong to the Hapalidiaceae (Melobesioideae) but are of uncertain generic placement. The type specimens of Lithophyllum hashimotoi, Lithophyllum minae, Lithothamnion huseinii and Lithothamnion tokiensis lacked sufficient data to allow for order, family, subfamily or genus placement within the Corallinophycidae. Lectotype specimens have been designated as necessary, and relevant historical, repository, geological, morphological and other data are presented.