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Show 1899.] ON THE ANTIPATHARIAN CORALS OF MADEIRA. 813 11. Notes on the Antipatharian Corals of Madeira, with Descriptions of a new Species and a new Variety, and Remarks on a Specimen from the West Indies iu the British Museum. By JAMES Y A T E JOHNSON, C.M.Z.S. [Received May 22, 1899.] The marine objects popularly called Black Corals are zoophytes which constitute the group of Antipatharia in systematic zoology. Some of them are much branched and resemble bushes that occasionally reach the height of four or five feet. Others extend their branches almost in one plane in a fan-like manner; others, again, are simple unbranched stems, slender and wire-like, that are sometimes found with a length of seven or eight feet. All are attached, when living, to submarine rocks or stones by a thiu spreading base. All have a hard horny axis of a black or brown colour, aud that axis is seen, on examining a section, to consist of concentric layers. Further examination will show that it has a fibrous structure. Stem and branches are frequently armed with minute spines arranged iu longitudinal or spiral series, but sometimes the stem and main branches are smooth and polished. The hard axis is secreted by the soft polypiferous ccenenchyma which clothes it. The polyps in the Madeiran forms have six (in one species twenty-four) simple tentacles. Spicula are not anywhere present, and thus the Antipatharia are easily distinguished from the Alcyonaria. Eight species of Black Coral belonging to six genera have been found at Madeira, more than one-thirteenth of the total number of known species. In the late George Brook's excellent Beport on the Antipatharia of the ' Challenger ' Expedition (1889) ninety-eight species were dealt with, but these included not only the forms collected by the naturalists of that expedition but all those previously described. The Beport is therefore a Monograph of the group. Until the publication of that work much difficulty was experienced in coming to a conclusion with regard to the discrimination of species and the identification of specimens, owing to imperfect description and confusion of nomenclature; and even now, notwithstanding that author's efforts, much remains to be done, especially in regard to our knowledge of the polyps, before satisfactory definitions are possible and the classification placed on a trustworthy basis. All the species of Madeira come from depths below 40 fathoms They are brought to the surface by becoming entangled now and then in the lines of the fishermen. Of the eight species of Black Coral here treated of, five have not hitherto been found elsewhere, and one of these is n o w described for the first time (Leiopaihes expansa). Another of the five species, having been confused with a West Indian species, is here distinguished by a fuller description, whilst a new name has P R O C . Z O O L . S O C - 1 8 9 9 , No. LIII. 53 |
