TRANSACTIONS OF THE SECTIONS. 61 



separated regions are found to contain some fossils that have a common type and are 

 identical in species, the study of organic remains should be considered as of paramount 

 importance by the practical geologist. 



On the Post- Tertiary Formations of Cormvall and Devon. By Mr. Bartlett. 



Mr. Bartlett detailed the circumstances under which these formations are found in 

 Devon and Cornwall, consisting of raised beaches, drifted deposits in caverns, and fis- 

 sures in lime rocks, and of submarine forests. Mr. Bartlett mentioned, in addition 

 to the caves hitherto described, one named Ash Hole, in Berryhead ; it was thirty 

 yards long and six broad, and on the materials filling the cave lay four feet of loam 

 and earth, containing land-shells of the genera Helix and Cyclostoma ; also marine 

 shells, such as the Mytilus of the coast, bones of the domestic fowl, and human bones, 

 mixed with pottery and various implements ; below these were found abundant re- 

 mains of the elephant, and the usual cavern debris. In the lacustrine deposits he 

 mentioned, as of usual occurrence, the remains of oak, ash, elm, willow, maple, &c. 

 and of ferns and Zostera. These he considered as belonging to a later epoch than 

 the cavern animals, which could hardly have existed at the same time with vegetation 

 resembling that of the present day. He then described some of the usual characters 

 of the raised beaches, which vaiy in elevation from twenty-five to thirty-five feet above 

 sea-level, and consist of terraces of fine yellow siliceous sand, containing pebbles of 

 chert, limestone, old red sandstone, greenstone, hsmatitic iron ore, &c.; together 

 with abundance of shells, — Purpura lapillus, Patella, Turbo, Nassa, Ostrea, &c. with 

 remains of Echinodermata, SepiadfP, and rarely of Gorgonite. These phenomena, 

 indicating changes in the relative level of land and sea, the author attributed to gal- 

 vanic action exerting itself along peculiar lines of geographical range, such as the 

 bottom of the British Channel, which had always been oscillating, from the earliest 

 tertiary era. 



An Account of the Fossil Orgajiic Remains of the South-east Coast of Corn- 

 ivall, and of Bodmin and Menheniott. By C. W. Peach. 



The line of coast examined commences at Veryan, four miles south of Tregony, and 

 extends eastward by Gorran, the Blackhead, and Fowey, to East Looe. The cliffs 

 are composed throughout of quartzose and slaty rocks, hitherto supposed by Mr. 

 Conybeare and others, who have referred to them in their writings, to be destitute of 

 fossils. But along the whole line Mr. Peach has detected traces of Brachiopodous 

 shells and corals, and the stems of Encrinites are of frequent occurrence. From Ve- 

 ryan to Gorran the quartzose rocks rarely contain traces of shells, but in the calca- 

 reous slates in contact with dykes of greenstones at Blackhead, remains of corals re- 

 sembling Turhinolopsis, and of the genera Cyathocrinus, Spirifera and Orthoceras, 

 occur. Eastward, at Pridmouth, a fine specimen of the Platycrinite was found, with 

 the column, pelvis, arms, &c. In the slate quarries of Fowey, remains supposed to 

 be those of fish, and corals of the genus Favosites, were detected. Near Polruan en- 

 crinital stems nearly a foot long occur, together with remains of Tfilobites, corals of 

 the genera Cyathophyllum and Favosites, Spirifera, Orthoceras, and a fossil with 

 structure resembling that of the Sepiada. At Pentlooe an equal- valved bivalve, re- 

 sembling Nucula, and a species of Orihis, have been found ; and at East Looe another 

 fine specimen of an Encrinite, with column, arms, and tentacula attached ; also spe- 

 cimens of Cyalhoci-inus, Fenestella, Turhinolopsis, and Orihis. At Bodmin the au- 

 thor had detected Encrinites in the slate quarries, and in those of Menheniott in 

 Liskeard, the eye of a Trilobite in good preservation. On the beach below the cliffs 

 at Port Mellin, near Mevagissey, the author observed traces of a lacustrine deposit, 

 containing roots and branches of trees, and the elytra of beetles, exposed after a 

 heavy gale. 



On the Stratified and Unstratified Volcanic Products in the neighbourhood of 

 Plymouth. By the Rev. D. Williams, F.G.S. 



Mr. Williams stated, that the prevalent association over the different regions of the 

 earth, of granite, gneiss, greenstones, porphyries, mica-, talc-, chlorite-, and clay- 

 slate, had f^or some time past induced him to suspect that such common assemblage 

 was not without its signification : recent observations in Devon and Cornwall had 

 convinced him, that there existed an intelligible relationship in the community of their 

 origin, viz. that they were all volcanic products. He would instance, first,' the gra- 



