Fig. 9. An enlarged view of fig. 10. "A shell of the genus _Sigaretus_."--_Mr. Parkinson._ Mr. Morris thinks it is merely an operculum of a small univalve. Fig. 11. A chambered cephalopodous shell (_Lituites lituus_, of Hisinger), from Silurian strata, Sweden. Figs. 12, & 13. These curious contorted bodies are named "_Vermiculitæ_" by Mr. Parkinson. They occur in the cream-coloured limestone of Pappenheim and Solenhofen. They are termed "_Lumbricaria colon_" by Goldfuss; and "_Cololites_" by M. Agassiz; the last-named eminent naturalist has demonstrated that they are the fossilized intestines of fishes.[53] [Footnote 53: See Dr. Buckland's Bridgewater Essay, vol. ii. plate 15.] [Illustration: Plate LVIII.] PLATE LVIII. Fossil Shells. Fig. 1. "Part of a hexahedral Serpulite."--_Mr. Parkinson._ Fig. 2. A silicified mass of delicate filiform serpulæ, from the upper greensand of Devonshire (_Serpula filiformis_, of Sowerby). Fig. 3. Portion of a species of _Siliquaria_, from tertiary strata, France. It is the shell of an Annelide related to _Dentalium_. Fig. 5. A spiral Serpulite (it resembles the _Serpula conica_); probably from the cretaceous beds of the Isle of Rugen. Fig. 6, is a piece of polished sandstone, from the upper greensand of Wiltshire, "the markings on which are produced by sections of a species of Serpula (_Vermetus concavus_, of Sowerby)."--_Mr. Morris._ Fig. 7. A species of _Vermetus_; from Bayonne? Figs. 8, & 9. A species of _Vermetus_ which abounds in the coarse arenaceous limestone of Bognor Rocks, in Sussex (_Vermetus Bognoriensis_, of Sowerby). Fig. 10. "A section of the shell of a Nautilus, to show that the siphuncle sometimes suffered distension."--_Mr. Parkinson._ Fig. 11. A species of Serpula (_Serpula ampullacea_, of Sowerby), from the chalk of Kent. Fig. 12. A fragment of the back or dorsal part of the shell of a fossil Nautilus (_Nautilus centralis_, of Sowerby), from the London clay, Brentford. The outer shell is broken away, and the siphuncle, traversing five of the septa of the chambers, is exposed. Fig. 13. "The outline of the back of a Nautilus."--_Mr. Parkinson._ Fig. 14. An Orthoceratite (_Orthoceras annulatum_, of Sowerby; _O. undulatum_, of Kissinger), from the Wenlock Limestone, Dudley. Fig. 15. A fragment of a fossil Nautilus (_Nautilus Parkinsoni_, of Mr. Edwards), from the London clay of Harwich. It shows the situation of the siphuncle and the form of the septa, as indicated by the sinuous transverse lines.