On the genus Synapta / by S.P. Woodward and Lucas Barrett ; (communicated by J.S. Gaskoin).

  • Woodward, Samuel Pickworth, 1821-1865.
Date:
1858
Catalogue details

Licence: Public Domain Mark

Credit: On the genus Synapta / by S.P. Woodward and Lucas Barrett ; (communicated by J.S. Gaskoin). Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    2 of the Celebes is a yard long, and called a “ sea-serpent” by the na- tives ! # Two other large species, described by Lesson, were said to create a burning sensation when handled; but it is not clear whether this was caused by the anchors, or by urticating organs, like those of the Actinia and JEolis. No such phsenomenon could be detected by Quatrefages or other observers who have handled the smaller Synapta when alive. The anatomy of these creatures appears to have been first in- vestigated by Leuckhart f, who examined the Synapta vittata of Forskal, and ascertained that it had no internal respiratory organs like the Holothuria. Anchors and plates attributed to this species, which comes from the shores of the Red Sea, near Suez, are to be found in the cabinet of every microscopic observer. The slides are prepared in Paris, and extensively re-manufactured in this country. The anchor-flukes are plain and simple, and the articular end of the shank is deeply subdi- vided. The plates are furnished with a raised arch at the smaller end, forming a sort of cavity for the reception of the anchor-stock. They are exactly- Uke those figured in Muller’s article, “ Ober den Bau der Echinodermen” (Berlin Trans. 1854, t. 6. f. IV), under the name of S. serpentine There is a woodcut of them in Carpenter’s work on the Microscope ; and figures are also given in the Micro- graphic Dictionary. Mr. Wm. Griesbach has a slide with the mi- liary plates, which are oval and granular, very numerous, and all alike. Prof. Forbes was unacquainted with the anchors of the British Synapta, and Dr. Carpenter in his last wrork (1857) says it is not known whether they have anchors, or wheels like Chiridota. We have obtained evidence of both the European Synapta from several British localities ; and as the published notices are scattered in many works, we propose to give some account of them, with figures of their spicula, and also to describe a new species from China. 1. Synapta digitata (Holothuria), Montagu. (PI. XIV. figs. 1-17.) The earliest account of this species appears to have been given by Montagu who discovered it on the coast of Devonshire, and cor- rectly observed its affinity with the Holothuria inharens of the Zoologia Danica, but pointed out its characteristic difference by the epithet “ digitata.” It has four fingers to each of the twelve ten- tacles, and a minute thumb which has been overlooked by all ob- servers except J. Muller. It was again found, prior to 1818, by Cranch (the Naturalist to the Congo Expedition), whose specimens are preserved in the British Museum §. In 1844 Mr. Joshua Alder discovered it on the west coast of Scotland, the most northern lo- cality yet known. He says in a letter:—“I dredged the true digi- * Dissertatio de Holothuriis, 4to. Turic. 1833. f Isis, 1831. f Linn. Trans, xi. p. 22. t. 4. f. 6. § Gray, Catalogue of British Radiata, p. 12.
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