Description of a rare species of worm shells, discovered at an Island lying off the north-west coast of the Island of Sumatra, in the East Indies

Abstract

The shells here described were discovered in a small island called Battoo, after a violent earthquake that occurred in the year 1797. Upon the receding of the inundation caused by the earthquake, they were seen protruding from a bank of slightly-indurated mud, in a small sheltered bay, surrounded by coral reefs. They were procured by means of a servant sent by Mr. Griffiths for that purpose, who was very expert in diving, and who stated that he found these shells sticking out of the mud to the extent of ten inches, or even more, and being from one to three fathoms under water. They were in considerable number, standing in different directions, and separate from each other. Mr. Griffiths was informed that the shells were filled with a soft gelatinous flesh, and that the animal threw out tentacula, resembling small Actiniæ, from the two apertures at the apex. They were easily extracted from their bed, but were all mu­tilated more or less: this, the author thinks, was occasioned by the earthquake. The longest of these shells that came into the possession of Mr. Griffiths was five feet four inches in length. The circumference at the base was nine inches, tapering upwards to two inches and a half. But others were of very different dimensions. The large end of the shell is completely closed, and has a rounded appearance: at this part it is very thin. The small end, or apex, is very brittle, and is divided by a longitudinal septum, which extends downwards eight or ten inches, into two distinct tubes, from whence protrude the tentacula already mentioned. The substance of the shell has a ra­diated appearance, and having an outer crust of a pure white colour, and an inside enamel of a yellow tinge. The external surface is often interrupted by a sudden increase of thickness, which probably indi­cates the different growths of the shells; but these interruptions are merely on the outside shell, and do not extend into the radiated sub­stance. The thickness of these shells varies very much; so also does their shape, some being nearly straight, others crooked and con­torted. Their internal surface is generally smooth, but is sometimes covered with excrescences resembling tubercles. There was no in­dication that the animal had adhered to any part of the shell.