. Bulletin of the British Museum (Natural History), Geology. 198 PALAEOZOIC CORAL FAUNAS counter septum, others half radius or slightly more in length. Nodes present on major and minor septa close to periphery. Aulos medium to thin walled, may be irregular in shape. Holotype. R46746 (S2275D). Rio Suripa section; Silurian, Ludlow. Paratype. R46747 (S2275D). Same locality and horizon as holotype. Description. Two fragments of small solitary corals embedded in grey mud- stone. External shape unknown. In cross-section, the corals are subcircular with a strongly longitudinally corru- gated epitheca
. Bulletin of the British Museum (Natural History), Geology. 198 PALAEOZOIC CORAL FAUNAS counter septum, others half radius or slightly more in length. Nodes present on major and minor septa close to periphery. Aulos medium to thin walled, may be irregular in shape. Holotype. R46746 (S2275D). Rio Suripa section; Silurian, Ludlow. Paratype. R46747 (S2275D). Same locality and horizon as holotype. Description. Two fragments of small solitary corals embedded in grey mud- stone. External shape unknown. In cross-section, the corals are subcircular with a strongly longitudinally corru- gated epitheca reflecting pronounced interseptal ridges. The peripheral stereozone is 0-2 mm thick. The major septa are thin, about 0-15 mm across, and reach within a short distance of the axis at the base of the calice. The axial ends of the septa have a pronounced club-shaped thickening bringing them into lateral contact to form a medium to thin walled aulos. There is little additional material reinforcing the structure. The aulos may be regular or irregular in shape and has an internal diameter of about o-8 mm. The minor septa are the same thickness as the major septa and contratingent with them. They may reach o-6 of the radius in length except for the counter-lateral minor septa which are equal in length to the counter septum. Both major and minor septa develop irregular rounded or sharp edged nodes (Knoten of Kullmann 1965), 0-5 mm from the epitheca, which may double or treble the normal septal thickness. The nodes partially close the space between adjacent major septa to produce a keyhole appearance at the peripheral end of the gap (see particularly PI. 1, fig. 7 and Text-fig. 4c). No longitudinal sections of the species are available. Signs of tabulae between the major septa in cross-section are extremely rare although sections of horizontal elements appear more commonly between the major septa and their contratingent minors. Coral diameters at the base of the calice are 5-0 mm with
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