COMMON LIMPE T,

The

or

IT

PATEL LA.

T is remarkable, that in the hiftories of shell-fish, and from very respectable authorities, the Limpet should be represented as a most inert, formless, and torpid animal, immoveably fixed to the fame rock *, and constantly adhering fo clofe, as rendered it a mystery which way they could fubfift t.

The general appearance of this fhell-fish, when found above low-water mark, and the difficulty of difengaging it from its place of abode, had first suggested these opinions, and continued to countenance them, in the view of fuch enquirers into nature, as have not given the subject a particular examination.

It was therefore prefumed, that it might be acceptable to thofe who have not opportunity of furveying the animals of the Patella race, in their native element, to have a delineation of the ftructure of one, as a fpecimen, prefented to them, with a narration of fome particulars in their manner of life.

The infide view of the fhell D, given at A, with the animal alive in it, fhews around B the front of a strong, cartilaginous, mufcular mafs, wherewith it adheres at pleasure with amazing firmness to the rocks, and by the various movements of which, it creeps along in search of pasture, with an equable steady pace, in any direction, as inftinct prompts. During this progrefs the horns or feelers feem actively engaged in examining the nature of the fubftances wherewith the rocks are covered, and no doubt have the capacity of ascertaining how far the courfe is eligible, and the fubftances good for food; for fometimes the feelers seem offended, and retract, and then the line of walk is altered. "Here," fays the Limpet, " am I travelling in fearch of "wholesome nourishment; if I find it in this field, I fhall remain, and exhaust its treasures; if not, I will feek after a richer foil, and productions of the rock that are more to my taste."

In the head of the animal magnified at C, in the middle of its strange mouth there is fhewn the form of a kind of grater, which it moves up and down with confiderable force and quickness; and feems to be an inftrument of teeth, provided by nature, for rubbing off the nutrimental fubftances from the rock and fea

weed.

• Buffon

+ Spectacle de la Nature.

2

The

The infide of the fhell is cloathed with a moveable membrane, finely ramified with purple and various-coloured veins, which terminate at the margin of it in a series of fibres, e e, feverally animated; these are a fet of retractile polype-like organs, which in various modes are ever waving about in the water, probably also inhaling nourishment; and may be the inftruments employed in making the continually neceffary additions to its fhell.

The filament which generally covers the infide of the shell, it can retract and expand at pleasure; and at a little distance from the edge, a curiously-wrought intef tine runs round it like net-work, each feveral part of which is often in motion, like the play of lungs.

While the Limpet was under confideration, there appeared several minute, uncommon living creatures darting about in the water, of a femi-transparent substance; two of these, which were got confined, fo as to be examined by the microscope, are figured on the plate at G g, and F f, (the small letters indicating their natural fize): unknown to what tribes they belong.

They were occafionally caught by the rapid movements of the tentacula of the Accom or Barnacle, H h, and instantly swallowed by it;-fome proof that its blind activity is not exerted in vain.

This genus is called by Linnæus, LEPAS. The specimen here produced at h, is of a very beautiful form; and feems fomewhat different from the Cornish (Br. Zool. vol. IV. plate XXXVII. fig. 6), or any of the other kinds there figured. But the inceffant celerity wherewith they play in the water, and the impoffibility of arresting them in an expanded state, evincing the difficulty of critically ascertaining their form, were an incitement to attempt it, and the chief reafon for giving it a place on the annexed plate; where the general appearance of its fibrous claws, or active tentacula, are represented at H. The object of thefe ftrictures being not fo much to distinguish shells by their external form, as to unfold the properties and œconomy of their living inhabitants.