286 Eoyal Society : — PROCEEDINGS OF LEARNED SOCIETIES. ROYAL SOCIETY. March 24, 1S70. — Lieut.-Gcneral Sir Edward Sabine, K.C.B., President, in the Chair. On the 3Iaclreporaria dredged up in the Expedition of H.M.S. * Porcupine.' By P. Maktix Duxcan, M.B. Lond., F.R.S., Sec. Geol. Soc, Professor of Geology in King's College, London. Professor Wyville Thomson, Dr. Carpenter, and Mr. Gwjn Jef-freys have placed the collection of stony corals dredged up by them in the ' Porcupine ' Expedition in my hands for determination. They have kindly afforded me all the information I required con-cerning the localities, depths, and temperatures in which the speci-mens were found. My report has been rendered rather more elaborate than I had intended, in consequence of the great consideration of Professor A. Agassiz and Count de Pourtales in forwarding me their reports * and specimens relating to the deep-sea dredging off Florida and the Havana. They have enabled me to offer a comparison between the British and American species, which I had not hoped to do before the publication of this communication. Contents. I. List of the species, localities, depths, temperatures. IL Critical notice of the species. III. Special and general conclusions. I. Twelve species of Madrcporaria were dredged up, and the ma-jority came from midway between Cape Wrath and the Faroe Islands. Others were also found off the west coast of Ireland. Many varieties of the species were also obtained, and some forms which hitherto have been considered specifically distinct from others, but which now cease to be sof. [See Table, p. 287.] List of species known only on the area dredged, or in the neighbouring seas. 1. Amphihelia atlantica, nobis. 2. ornata, nobis. 3. Allopora oculina, Ehr(nher<j. List of species common to the area and to the Florida and Havana deep-sea faunas only. 1. Balanophj'Uia socialis, Pourtales, sp. 2. Amphihelia profunda, Pourtales, sp. 3. Pliobothrus symmetricus, Pourtales, sp. * Contributions to the Fauna of the Gulf-stream at great depths, by L. F. de Pourtales, 1st & 2ud series, 1808. Bull. Mus. Comp. Zool. Harvard College, Cambridge, jMass., Nos. G & 7. t One specimen came from the ' Lightning ' Expedition. It must be remembered that all the deep-sea corals kuown to British naturalists were not dredged up. The Sfi/Iastcr rosea, for instance, was not amongst the collection.