In a great and very ancient Wall of Free-Stone in the _Benedictins Abby_ at _Caen_ in _Normandy_, facing Southward, there are to be found many Stones so eaten by Worms, that one may run his hand into most of the Cavities which are variously fashion'd, like the Stones, which I have seen wrought with so much Art in the _Louvre_: In these cavities there is abundance of live-Worms, their excrement, and of that Stone-dust, they eat. Between many of the Cavities there remain but leaves, as it were, of Stone, very thin, which part them. I have taken some of these living Worms, which I found in the eaten Stone, and put them into a Box with several bits of the Stone; leaving them there together for the space of eight days; and then opening the Box, the Stone seem'd to me eaten so sensibly, that I could no longer doubt of it, I send you the Box and the Stones in it, together with the living Worms: and to satisfie your Curiosity, I shall relate to you, what I have observed of them both _with_ and _without_ a _Microscope_. {322} These Worms are inclosed in a Shell, which is grayish and of the bigness of a Barly-corn, sharper at one end, than the other. By the means of an excellent _Microscope_ I have observ'd, that 'tis all overspread with little Stones and little greenish Eggs; and that there is at the sharpest end a little hole by which these Creatures cast out their excrement, and at the other end, a somewhat bigger hole, through which they put out their heads and fasten themselves to the Stones, they gnaw. They are not so shut up, but that sometimes they come out, and walk abroad. They are all black, about two _Lines_ of an inch long and three quarters of a _Line_ large. Their Body is distinguish't into several plyes, and near their head they have three feet on each side, which have but two Joynts resembling those of a Lowse. When they move, their Body is commonly upwards, with their mouth against the Stone. They have a big head, somewhat flat, and even, of the colour of a Tortoise-Shell, braunish, with some small white hair. Their mouth is also big; where may be seen four kinds of Jaw-bones, lying crossewise, which they move continually, opening and shutting them like a pair of _Compasses_, with four branches. The Jaws on both sides of the mouth are all black, the nether Jaw hath a point like the Sting of a Bee, but uniform. They draw threds out of their mouth with their fore-feet, using that point to range them, and to form their Shells of them. They have Ten Eyes, very black and round, which appear to be bigger than a Pins head. There are five of them on each side of the head, standing after this manner, [Illustration]