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 perish. These bodies, thus attached, are the strongest proof we can desire, that the Belemnite is of marine production. Indeed it may be objected, that the bones of quadrupods, wood, and stone have these bodies adhering to them, and therefore may be said to be marine, as well as the Belemnite. But when we bring them to chemical tryal, the objection vanishes; for the bones either come out of the furnace with a black core, or they are reduced to ashes; whereas the Belemnite is changed into a fine calx, after the manner of all testaceous bodies, and is converted into a species of phosphorus. The oisters, having no loco-motion, frequently affix themfelves to other bodies, that they may be better able to stem the tides, and currents, which might otherwise carry them from their proper beds, and places of feeding. This attachment to other bodies no way incommodes them, because they increase the dimensions of their shells by adding fresh laminæ inwardly: the first formed laminæ, being, as it were, excluded, lie in the manner of tiles upon the roof of a house, and exhibit the several steps or stages of their growth.

I believe a Belemnite is very rarely found perfect in the fossil state: those in gravel-beds have suffered very much by being rubbed against stones, &c. by the fluctuating waters: those, which we find in rubble at Garsington-pitts, have many adventitious bodies adhering to them, and consequently were deserted by