S. V. WOOD ON A NEW DEPOSIT OF PLIOCENE AGE 



Discussion. 



Dr. GwYN Jeffeets expressed his regret that the author of this 

 important communication was prevented by illness from being pre- 

 sent at the meeting, and said that the paper exhibited indications of 

 the great energy possessed b}^ the author notwithstanding his bad 

 state of health. Great credit was also due to Mr. Eobert Bell for 

 his share of the work. After careful examination Dr. Jeffreys re- 

 cognized 50 species among the fossils obtained from the deposit at 

 St. Erth : but from the number given by Mr. Wood he deducted 

 5 for duplicates, and one which he thought was not a moUusk. 

 There were thus 44 or 45 species, out of which 11 or 12 are recent 

 and 33 or 34 extinct. Of the latter 11 only are known to him from 

 Tertiary deposits, 4 being of Miocene age, and all of them Pliocene. 

 22 species were unknown to him either as Tertiary or recent. For 

 the accurate determination of the species, the collection, when more 

 complete, would have to be critically compared with recent forms, 

 and the necessary allowance made for that slight divergence which 

 was always observable in the shells of species whose existence 

 extended over a long period of time. Dr. Jeffreys thought that the 

 author had not quite sufficient knowledge of recent Mollusca for his 

 determinations to be thoroughly accurate. The list of shells needs 

 a careful re-comparison with the species contained in the Tertiary 

 collections of Europe. 



He further remarked that no deposits of Glacial age have hitherto 

 been found in the south of England. He was not clear whether the 

 St. Erth deposit was of Older Pliocene or possibly of Upper Miocene 

 age. Nassa serrata^ Brocchi, was one of the few species in the list 

 identical with Crag forms, namely Buccinum reticosum of Sowerby. 

 The deposit did not seem to him to be connected with any Crag bed. 

 A bed near Antibes, in the South of Prance, seemed to him to resemble 

 the St. Erth deposit in many of its characters, and the Mollusca of 

 these two deposits should be critically compared. 



Prof. Pkestwich said that this discovery of Mr. Searles Wood was 

 the most interesting that had been made upon the southern coast of 

 England for many years. It was the first clear evidence from fossils 

 of a depression in Cornwall since Palgeozoic times, as the beds near 

 St. Austell contain no organic remains. The high- and low- level 

 beaches of Jersey and Guernsey are also unfossiliferous. He felt the 

 same difficulty as Mr. Wood in correlating the beds in Brittany. 

 The beds at Bosq d'Aubigny, in IS^ormandy, present many points of 

 analogy with those of St. Erth. There is the same preponderance 

 of Subapennine and Mediterranean species, with many Crag fossils, 

 but the species are different. 



Mr. Etpteeidge thought that the author had been rather hurried 

 in drawing his conclusions, and that more stratigraphical and geo- 

 graphical evidence as to the distribution of the bed, and a careful 

 survey of the neighbouring coast were requisite. He said that 

 Mr. Solly had tried to make out the succession of the clays, and 



