the tooth showing its cup-like
shape. (Original drawings.)]

I have examined twelve of these rings in the British Museum, through
the kindness of Sir Charles Read, P.S.A., the Keeper of Mediaeval
Antiquities, and four in the Ashmolean Museum at Oxford. Two of these
are of chalcedony, with a figure of a toad roughly carved on the
stone, and are of a character and origin different from the others.
The others, which are the true and recognised "toad-stones" or
"_Bufonius lapis_," are circular, slightly convex "stones," of a drab
colour, with a smooth enamel-like surface. They are plate-like discs,
being of thin substance and concave on the lower surface, which has an
upstanding rim. I recognised them at once as the palatal teeth of a
fossil fish called "Lepidotus," common in our own oolitic and wealden
strata, and in rocks of that age all over the world. I give in Fig. 5
a drawing of a complete set of these teeth and of a single one
detached. They were white and colourless in life, but are stained of
various colours according to the nature of the rock in which they were
embedded. A drab colour like that of the skin of the common toad is
given to them by the iron salts present in many oolitic rocks; those
found in the wealden of the Isle of Wight are black. That the
"toad-stones" mounted in ancient rings are really the teeth of a fish
has been already recorded by the Rev. R. H. Newell ("The Zoology of
the English Poets," 1845), but he seems to be mistaken in identifying
them with those of the wolf-fish (Anarrhicas). They undoubtedly are
the palatal teeth of the fossil extinct ganoid fish Lepidotus.

Before leaving the queer inventions and assertions of the old writers
about these fossil teeth, which they declared to be taken out of the
toad's head, let me quote one delightful passage from a contemporary
of Shakespeare (Lupton: "A thousand notable things of sundry sortes.
Whereof some are wonderful, some strange, some pleasant, divers
necessary, a great sort profitable, and many very precious," London,
1595). "You shall know," he says, "whether the Toadstone called
'crapaudina' be the right and perfect stone or not. Hold the stone
before a toad, so that he may see it. And if it be a right and true
stone, the toad will leap towards it and make as though he would
snatch it from you; he envieth so much that a man should have that
stone. This was credibly told Mizaldus for truth by one of the French
King's physicians, which af