II.—On the Structure of Cleistopora (Michelinia) Geometrica, Edwards & Haime, sp.

Extract

In their great work upon the Palæozoic Corals (Polypiers Foss. des Terr. Pal. p. 252, pl. 17, figs. 3, 3a, 1851) Milne Edwards and Haime describe and figure, under the name of Michelinia geometrica, a remarkable little Coral from the Devonian rocks of France. By the kindness of Dr. Daniel Œhlert, of Laval, whose researches upon the stratigraphy and palasontology of the French Devonian rocks are well known, I have been enabled to examine some well-preserved examples of this interesting form, and have determined some new facts as to its internal structure. Investigation by means of thin sections has, in fact, shown that this Coral has in reality no close relationships with the genus Michelinia, but that its affinities are rather with Protarcea, E. & H. It differs, however, in important structural features from Protnræa, and appears to form the type of a new genus to which the name Cleistopora may be given.