POSSIL FAUNA. 133 



PLATE LVir. 



Fossil Shells. 



Figs. 1, & 3. Upper and under view of a discoidal spiral univalve shell [Euomphalus pentan- 

 gulatus, of Sowerby), from the mountain limestone of Derbyshire. The extinct 

 genus Euomphalus, a name suggestive of the deeply excavated disk, comprises many 

 species which occur in the Silurian, Devonian, and Carboniferous formations. The 

 shell has chambers, or rather obsolete cavities sealed up by a shelly partition, in the 

 abandoned part of the spire.^ 



Fig. 2. An elegant univalve shell, completely silicified or transmuted into flint {Natica canrena, 

 of Parkinson, Natica Gentii, of Sowerby), from the upper greensand of Blackdown. 



Figs. 4, & 6. Two views of the same specimen; a univalve {Nerita conoidea, of Lamarck), in 

 which the apex or upper part is destroyed, and the interior of the shell is filled with 

 yellowish brown chalcedony ; in fig. 4, a cast of the spire is seen, and in fig. 6, the 

 mouth of the shell, with the chalcedony partially filling up the interior. From 

 tertiary strata near Paris. 



Fig. 5. A beautiful fossil univalve shell, from the " Eed Crag " of SuiFolk, known to collectors 

 as the " Essex reversed whelk," from the spire being coiled in the opposite direction 

 to the common mode ; the mouth is consequently situated to the left of the observer ; 

 the same species occurs with the spire in the usual direction. This shell is the 

 Murex {Fusus) contrarius, of Parkinson. 



Figs. 7, & 8. Under and upper view of another species of Euomphalus {E. rugosus, of Sowerby), 

 from the Wenlock limestone, Dudley. 



Fig. 9. An enlarged view of fig. 10. "A shell of the genus Sigai-etus." — 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 " Vermicnlifce " by Mr. Parkinson. 

 They occur in the cream-coloured limestone of Pappenheim and Solenhofen. They 

 are termed " Lumhricaria colon" by Goldfuss ; and " Cololites" by M. Agassiz ; the 

 last-named eminent naturahst has demonstrated that they are the fossilized intestines 

 of fishes.^ 



' Medals of Creation, pp. 425—427. 



- See Dr. Buckland's Bridgewater Essay, vol. li. plate 15. 



