go THE JEWEL IN THE TOAD'S HEAD 



called batrachite, or brontia, or ombria. His description 

 exactly corresponds with the " toad-stones " which are 

 well known at the present day in collections of old rings. 



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-stone " or " lapis Bufonius" 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 are 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 extincb 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 



