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.

    7/10 page 5
    logia Danica ’ (1/81). The anchors and plates are also figured in the admirable Memoir of Duben and Koren * * * §. The ana- tomy of this species is described at some length by M. Quatre- fages f, who regarded it as a new species, and called it S. Duverncea. These specimens were obtained on the coast of Britany, at the Isles Chaussey near St. Malo, where they were very abundant in the mud near low water, and attained a length of 10 to 18 inches, with a dia- meter of 5 to 12 lines. The anchor-plates of this species (fig. 19) more nearly resemble those of the Red Sea S. vittata than the last. They are oval, with no arch or process at the articular end, and the disk is perforated by six oval cells surrounding a central opening each with a scolloped border, as in S. vittata. The anchors have serrated flukes, the serrations varying from 3 to 7; and the anchors are sometimes shorter than the plates, some- times considerably longer (figs. 18, 21). The miliary granules are few, and confined to the muscular bands ; they are onlv half as long as in S. diqitata, and rudely crescent- shaped (fig. 20). A specimen of this Synapta was obtained by Mr. Henslow at Aberystwith, and communicated in 1819 to Dr. Leach, who labelled it “ Jemania Henslow ana.9' It is a small individual with imper- fectly developed spicula, but showing the characteristic pinnate ten- tacles. In June 1856 Mr. J. W. Wilton, of Gloucester, found another example at Criccieth, on the same coast of Cardigan Bay. It was discovered under a stone, at low water, and presented the appear- ance of “ a clear pinkish waving worm, about 3 inches long, with a number of little papillae all over it, and five faint longitudinal bands from head to tail. It had twelve tentacles, with five digits on each side. It was perpetually waving and swelling in one part, contract- ing in another J. It lived but a short time, and finally constricted itself and broke up into half a dozen fragments.” In February 1856 Mr. E. C. Buckland obtained a finer specimen- under similar circumstances, in Lihou Bay, Guernsey. A micro- scopic preparation of the skin of this specimen shows 150 anchors in the field of the inch object-glass (^ inch diameter) ; and the an- chors are more than half as long again as the plates §. Mr. Cocks, who met with Synapta inhcerens on the coast of Corn- wall, regarded it as a variety of S. digitata. He describes it as having “ 13 digitated pinnse on each tentaculum. Length of speci- mens procured from 1 to inches by y^th to -|-th of an inch. Found in hard and stony soil; Helford, scarce ; Falmouth, very rare. I have kept them alive for months in sea-water procured from Helford * Proceedings of the Royal Academy of Sciences, Stockholm, 1846. t Annales des Sciences Nat. 2 ser. 1.1-7. Zool. p. 19. X Forskal named one species Synapta reciprocans, on account of these remark- able muscular movements. § “ Slides ” of this specimen are in many cabinets, with a red label, but with no specific name or locality.
    No text description is available for this image
    No text description is available for this image
    No text description is available for this image