Observations on the development of the medusæ / by John Reid.

  • Reid, John, 1809-1849.
Date:
[1848]
Catalogue details

Licence: Public Domain Mark

Credit: Observations on the development of the medusæ / by John Reid. 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.

    10/16
    ciently, at least as far as I can make out, to justify me in regard- ing it as a distinct species. If this should be confirmed, I would propose to name it Actinia cylindrica. Body elongated, cylindrical, free; tentacula uniserial, submarginal; mouth elongated upwards, forming a conical tube with small pro- cesses attached to its margin. This animal was found in St. Andrew's Bay, by Mrs.Macdonald and myself about two years ago, immediately after it had been thrown ashore during a storm, and it was kept alive for three days. Fig. 21 (Plate VI.) is a representation of the form of the animal of the natural size. The body is cylindrical and marked by longitudinal lines. The inferior fourth of the body is translucent, more contractile than the upper part, and sometimes assumes nearly a conical form with the apex downwards. The upper three-fourths of the body are opake and of a faint pink colour. The tentacula are twelve in number, ranged in a single row, smooth on the surface, of a light pink colour, and having their internal or oral surface crossed by four zigzag white lines (fig. 22). They are elongated trans- versely or flattened from within outwards, and taper towards their free extremity. They were never seen more elongated than what is represented in fig. 21, but as the animal appeared to be languid, it is quite possible they are capable of greater elongation. AVhen contracted to the utmost they formed little conical emi- nences, projecting outwards and upwards, and were seen to be attached immediately below the outer margin of the disc. Twelve bands of a faint reddish brown colour and adhering along then- edges, radiate inwards from the circumference of the disc, con- verge at its centre, and prolong themselves upwards to form the mouth, or rather the lips. The margin of the lips is surrounded by twelve small processes, six of which are very minute; these processes are of a triangular form and of an orange colour, except at the edges, which are translucent. This prolonged mouth did not always occupy the centre of the disc, but could be directed towards any part of the margin. The external sac sent strong partitions inwards, the position of which was marked by the longitudinal lines on its outer surface, and in the interstices of these partitions the ovaries were placed. This animal in many respects closely resembles the Buanthos Scoticus of Professor E. Forbes*, and the chief difference between them is found in the structure of the mouth. * Annals of Natural History, vol. v. p. 180.