in natural history, a name name given by Dr. Woodward to those kinds of fossil coralloide bodies which the generality of writers had called, after Dr. Plott, porpita. These are usually small, and of a roundish, but flat, figure; they are hollowed on one side with a sort of umbilicus, and striated on the other; they are found on the ploughed lands in Oxfordshire, and some other of our midland counties, and in other places, buried in the solid strata of stone; they are sometimes yellowish, sometimes brownish, and are from the breadth of an inch to a fourth part or less of that size; when broken, they are usually found to consist of a kind of spar, not unlike that of which the shelly coats of the echinidae, or the lapides indici, and other species of echini consist in their fossile state; and in some of them the ridges and striae are thick set with little knobs and tubercles. The basis in some of these is flat, as it is in others rising in form of a circular elevation from the umbilicus, and others have a circular cavity in the same place.