leaves, and every one of them in the same Shell, exactly one like another, which I was able to discover plainly enough with my naked eye, but more perfectly and distinctly with my Microscope; all these sutures, by breaking some of these stones, I found to be the termini, or boundings of certain diaphragms, or partitions, which seem’d to divide the cavity of the Shell into a multitude of very proportionate and regular cells or caverns, these Diaphragms, in many of them, I found very perfect and compleat, of a very distinct substance from that which fill’d the cavities, and exactly of the same kind with that which covered the outside, being for the most part whitish, or mother-of-pearl colour’d.

As for the cavities between those Diaphragms, I found some of them fill’d with Marle, and others with several kinds of stones, others, for the most part hollow, onely the whole cavity was usually covered over with a kind of tartareous petrify’d substance, which stuck about the sides, and was there shot into very curious regular Figures, just as Tartar, or other dissolv’d Salts are observ’d to stick and crystallize about the sides of the containing Vessels; or like those little Diamants which I before observed to have covered the vaulted cavity of a Flint; others had these cavities all lin’d with a kind of metalline or marchasite-like substance, which with a Microscope I could as plainly see most curiously and regularly figured, as I had done those in a Flint.

From all which, and several other particulars which I observ’d, I cannot but think, that all these, and most other kinds of stony bodies which are found thus strangely figured, do owe their formation and figuration, not to any kind of Plastick virtue inherent in the earth, but to the Shells of certain Shel-fishes, which, either by some Deluge, Inundation, Earthquake, or some such other means, came to be thrown to that place, and there to be fill’d with some kind of Mudd or Clay, or petrifying Water, or some other substance, which in tract of time has been settled together and hardned in those shelly moulds into those shaped substances we now find them; that the great and thin end of these Shells by that Earthquake, or what ever other extraordinary cause it was that brought them thither, was broken off; and that many others were otherwise broken, bruised and disfigured; that these Shells which are thus spirallied and separated with Diaphragmes, were some kind of Nautili or Porcelane shells; and that others were shells of Cockles, Muscles, Periwincles, Scolops, &c. of various sorts; that these Shells in many, from the particular nature of the containing or enclos’d Earth, or some other cause, have in tract of time rotted and mouldred away, and onely left their impressions, both on the containing and contained substances; and so