THE
QUARTERLY JOURNAL
OF
THE GEOLOGICAL SOCIETY OF LONDON.
Vol. XXXIII.
Every student of the geology of the Cotteswolds has recognized a band at the base of the Inferior Oolite under the name of the "Cephalopoda-bed," so named from the important list of Ammonites, Nautili, and Belemnites which it has been found to contain.
To quote from Mr. Hull's 'Memoir on the Geology of the Country around Cheltenham,' "This bed had been long known to geologists as 'the ammonite bed;' but the ammonites were supposed characteristic of the Inferior Oolite, and its true importance was over- looked. Dr. Wright, however, found that the species were identical with specimens from the Upper Lias of Whitby, in Yorkshire. About the same time the work of M. D'Orbigny made its appearance, wherein nearly all the cephalopoda from the ammonite bed arc figured and described as 'Toarcien' or Upper Lias forms, while even in our own district several of the species were known to be characteristic of the Upper Lias Shale" (p. 26).
Mr. Hull refers to a paper by Dr. Wright in the 'Proceedings of the Geological Society,' vol. xii., in support of the view that the Cotteswold Cephalopoda-bed belongs to the Upper Lias and not to the Inferior Oolite, and, further, that the learned Doctor had traced it to the Dorsetshire coast; and, indeed, in this very paper we find the following remarks upon sections at Half-Way House and Brad-
