Clypeina lagustensis n.sp., a new calcareous alga from the Lower Tithonian of the Lastovo Island (Croatia)

Clypeina lagustensis n.sp. has been found in the Lower Tithonian deposits of the Lastovo Island (Dalmatia, Croatia). It is visually similar, obviously related and in some sections appearing almost identical, to Clypeina jurassica FAVRE, from which it differs by visible swellings and thinning of the central cavity, more pronounced distance between neighbouring whorls of fertile branches, and shape and structure of the interverticillate thallus parts, characterized by having well developed, hairy, sterile branches. These, after emerging from the exit pore, divide into several bundles which form a common turf with a calcareous envelope in the proximal part.