Umbellula, Or Cluster Polyp

Abstract

ABOUT six months since (vol. x. p. 142) we referred to a letter from Prof. Wyville Thomson, in which he mentions having brought up from a depth of nearly 1,500 feet, between Prince Edward's Island and the Crozets (Kerguelen's Land), specimens of an Umbellula. When the Challenger was between the coasts of Portugal and Madeira, several specimens of another species of the same rare genus, but from a depth of about 2,000 feet, were also dredged up. The history of these curious Cluster Polyps is interesting. Some hundred and twenty years ago, and some one and twenty years before M. Kerguelen discovered the land now bearing his name, Capt. Adriaanz, the master of the whaling-ship Britannia, being then in lat. 790° N., and about eighty miles from Greenland, on pulling up his sounding line, found two specimens of a large plant-like polyp clinging to it; the length of the stem of the larger specimen was six feet, and he noted that the expanded flower-like polyp which was at one end of the stem was of a fine bright yellow colour. Struck by their size and beauty, and the strangeness of such creatures living at a depth in the sea of more than 220 fathoms, he brought them home to his friend Mr. Dunze, of Bremen, who had been a pupil of the illustrious Haller. Mr. Dunze gave the smaller specimen to Christlob Mylius, a Professor of Botany at Leipzig, and the larger to Peter Collinson, F.R.S.; this latter gentleman gave it to John Ellis, of zoophyte fame, to describe, which he did in the Philosophical Transactions for 1752, accompanying his description with a plate. What became of this specimen is unknown. Mylius's one found its way into a collection in Göttingen, and was not to be found there by Pallas in 1766. No specimens being found for thus more than a century, an air of uncertainty hung round this Cluster Polyp, and its portrait, so often copied in our text-books, seemed to be all one was likely to know about it. It was, therefore, with the greatest delight that the writer of these lines, in the summer of 1872, saw two specimens of Umbellula in the Swedish Museum of Natural History at Stockholm; one rare object after another had been shown to him by Prof. Lovén; but the Umbellula, though the last, was not the least of the treasures accumulated therein by this esteemed professor, who stated that Mr. J. Lindahl had dredged them up during the expedition of H.S.M. Ingegerd and Gladan to the Greenland Seas in 1871. Within the last few days we have received from Stockholm a quarto memoir, “Om Pennatulid-slägtet Umbellula af Josua Lindahl,” with three plates. This memoir was read before the Royal Swedish Academy in February 1874, and describes the two specimens as two species, tinder the names of U. miniacea and U. pallida. Prof. Kollikerhas also described one of the species found during the Challenger expedition as U. Thomsoni, making four species of the genus now described. It is marvellous what changes have taken place in our knowledge of the Natural Sciences in the interval between the description of Ellis's species and those so excellently described and figured in the memoir before us. Tke other genus Grinilium of the family Umbellulinæ, found about 1858 in a depth of 2,700 fathoms in the Banka Sea, will, we trust, be re-discovered by Prof. Wyville Thomson. It is only known by a fragment of the stem in the Leyden Museum, the crown of polyps having fallen overboard as Capt. Siedenburg, after whom the species is called, was pulling in the line to which it clung.