I have been favoured from time to time by M. Rigaux, of Boulogne, with specimens of corals for determination, which had been collected by him in the Great Oolite and Coral Rag of the Boulonnais. He has quite recently very kindly afforded me the additional opportunity of studying the whole of his collection of specimens; and the results of a comparison made between them and English species will form the substance of the present paper. It will be observed that I now regard Isastræa moneta as a second species of Bathycœnia its very great similarity to the Fairford species, Bathycœnia Slatteri, on which I founded the genus, having been already noticed by me. The discovery of some forms apparently allied to that genus, which nevertheless are found to possess well-developed tabulæ, renders the position of Bathycœnia in the Eusmilinæ more than doubtful. In my paper on the Corals of the Great Oolite, I hazarded some remarks, accompanied by explanatory figures, on a species of coral from the bottom of the Great Oolite near Stonesfield, which from the presence of distinct tabulæ and the very feeble development of its septa, I placed, though not without some hesitation, among the Zoantharia Tabulata. For that species, if it proved to be distinct from the one on which was founded the genus Cyathophora , the generic name Depaphyllum was proposed. But I am still in uncertainty as to the proper generic nomenclature of the species, because I do not yet know whether the genus Cyathophora