Silurian rugose coral Schlotheimophyllum Smith, 1945 from the Upper Visby Beds of Gotland, Sweden

A rich (about 60 specimens) collection of Schlotheimophyllum, large rugose corals from the Silurian of Gotland, Sweden, was studied. Although the material is mostly fragmentary (beach pebbles), the presence of growth lines, clearly seen in thin sections, provides reliable numerical data. Analyzed were corallum shape, septal numbers, and aspects of coloniality. Uniformity of variability spectra of these parameters indicates that all of the material studied belongs to a single, variable species, which is Schlotheimophyllum patellatum (Schlotheim, 1820).