[From OuR. OWN. CorresPONDENT. | Paris, Friday.—Miners who were sinking a shaft at Gager, near Rodez, found at a depth of 750 ‘feat an‘oyster bed: in’ a com plete state of petrifaction, nestling between the chalk and the‘coal formation. _ 7 The bed is well stocked with both mussels and oysters, some of which weigh a pound and a half avoirdupois. The bi-valves can easily be opened by tapping the shell with a mallet, and the oysters and mussels them selves are petrified as well as the shells. The inside of the shells is as brilliant ,and as shining as when the molluscs were fresh and good to eat.