62 



THE GEOLOGIST. 



MOLLUSCA. 



Oiihoceras sulcatum, Flem. 



Goldfussianum, Kon. 



Naticopsis plicistria, Phil. 

 Loxonema rugifera, Phil. 

 Euomphalus carhonarius, Sow. 

 Pleurotomaria decipiens, McCoy. 



aiomaria, Phil. 



PlatyscMsma helicoides, Sow. 

 Bellerophon Urii, Flem. 

 Orthis 7'esupinata, Mart. 



Michelini, Kon. 



Strophomena crenistria, Phil. 

 Productus Martini, Sow. 



punctatus, Mart. 



scabriculus, Mart. 



spimdosus, Sow. 



Jimhriatus, Sow. 



latissimus, Sow. 



Flemingii, Sow. 



semireticulatus, Mart. 



Chonetes sordida, Sow. 



Dalmaniana, Kon. 



gibberula, McCoy. 



Spirifer trigonalis, Mart. 



glaber, Mart. 



Uneatus, Mart. 



octoplicatus, Sow. 



Edmondia sulcata, Phil. 

 Sanguinolites iridinoides, McCoy. 



transversa, Port. 



variabilis, McCoy. 



Aviculo-pectendocens, McCoy. 



BRYOZOA. 



Fenestella plebeia, McCoy. 



crassa, McCoy. 



undidata, Phil. 



Glauconome pluma, Phil. 

 Sulcoretepora parallela, Phil. 



CORALS. 



^ w lophyllum fungites, Flem. 

 Lithodendron irregidare, Phil. 

 Stenopora tiimida, Phil. 

 Favosites parasitica, Phil. 

 serialis, Port. 



The calcareous shale is remarkably full of fossils ; indeed it is 

 almost entirely formed of Productus Flemingii and Spirifer trigonalis. 

 Being exposed to the weathering influence of the tide, which washes 

 away the softer matrix, the fossils stand out in bold relief, and fine 

 specimens of the Productus can be obtained, showing beautifully the 

 curious internal structure of the shell. 



The limestone which forms the bold headland of Ebbs Nook is, 

 however, the most interesting of the group, from its peculiar orga- 

 nisms, its mineral composition, and picturesque appeariince. It is 30 

 feet in thickness ; and, being very hard, resists more effectively than 

 the other rocks the destructive action of the sea. Besting, however, 

 on a soft shale which is easily broken up and washed away by the 

 tides, this superincumbent limestone is deprived of support, and from 

 time to time large masses tumble down from the cliff. It now forms 

 a narrow point running out into the sea for about one quarter of 

 a mile ; but the tides and high seas are still working away the lower 

 and softer beds which connect this promontory with the land, and in 

 the course of a few centuries it will become an island on the flow of 

 every tide. This limestone is of a buff colour and generally of a 

 crystalline structure. It is a magnesian limestone, being composed of 

 carbonate of magnesia and carbonate of lime. Besides containing 



