Fig. 9. Sections of a pyritous cast of an Ammonite, showing the sinuous edges of the septa. [Illustration: Plate LXI.] PLATE LXI. Fossil Cephalopoda, &c. Fig. 1. Part of the cast of a species of Hamite (_Hamites intermedius_, of Sowerby), from the Gait of Folkstone. The name _Hamites_ was employed by Mr. Parkinson to designate a genus of chambered shells, in which the direction of the spire, instead of being straight, as in _Baculites_, or discoidal, as in _Ammonites_, was bent like a hook beyond the inner reflected part. All the specimens here figured are but fragments.[55] [Footnote 55: Medals of Creation, vol. ii. p. 500.] Figs. 2, & 5. Portions of _Hamites intermedius_, of Sowerby. Fig. 3. _Hamites plicatilis_, of Sowerby. Fig. 4. A fragment of _Hamites rotundus_, of Sowerby. Figs. 6, & 7. Two views of a species of an extinct genus, the shells of which, though not chambered, are supposed to have been inhabited by Cephalopoda, like the recent Argonaut. The specimen (_Bellerophon costatus_, of Sowerby) is from the Mountain limestone of Derbyshire.[56] [Footnote 56: Ibid p. 477.] Figs. 8, & 9. An Ammonite with a contracted aperture, and three deep constrictions across the disk. From the Inferior oolite of Normandy. Figs. 10, & 11. Two specimens of "_Scaphites_, or Boat-like Ammonite," of Mr. Parkinson. A remarkable cretaceous genus of extinct cephalopoda. The specimens figured are from the Lower chalk of Sussex (_Scaphites costatus_, of Mantell; _S. equalis_, of Sowerby). Fig. 12. Cast of a spiral chambered shell, called _Turrilite_, of which many species occur in the lower cretaceous strata (_Turrilites costatus_, of Langius). The quarries of lower chalk at St. Catharine's Mount, near Rouen, in Normandy, have long been celebrated for the number and perfection of specimens of this elegant type of cephalopodous shells. The first known English examples of this genus, as well as of Scaphites, were discovered by me in the chalk marl, at Hamsey, near Lewes, in Sussex, in 1810. Several very fine specimens of a large species (_Turrilites tuberculatus_), some of which are more than two feet in length, have been obtained from the same strata. The tubercles on the casts of this species are the bases of strong spines. The siphunculus, in the state of a pyritous cast, is preserved in some examples.