XIX. On a new Genus of Fossil Multihcular Shells, found in the 

 Slate-Rocks of Cornwall. Bij D. T. Ansted, B.A. of Jesus 

 College; Fellow of the Society, and of the C^eological Society. 



[Head February 26, 1838.] 



It is not many years since the slate-rocks of Cornwall were de- 

 scribed as contemporary in their formation with the Granite, and other 

 igneous and altered rocks of that county. They were of course pre- 

 sumed at that time to be absolutely without trace of fossils ; and 

 when remains of organic life were first observed, the very possibility 

 was questioned ; but, after some doubt and sufficient inquiry, the fact 

 was admitted, to the overthrow of the theory alluded to. 



Since it has been granted that fossils may be expected in these 

 beds, the search after them has not been unattended with success. 

 Among others. Professor Sedgwick, during his geological researches in 

 the South-west of England, has obtained many, in various states of 

 preservation, which, with a few collected from the neighbourhood of 

 Petherwyn, are now in the Woodwardian Museum ; and it was during 

 the temporary arrangement of these specimens, that I was struck witii 

 the occurrence, of what seemed to me a new genus of midtilocular 

 shells, and induced to lay this paper before the Society. 



. The rest of the organic remains consist chiefly of fossil marine 

 vegetables ; many shells allied to terebratula ; several species of ui- 

 thoceratites ; portions of the stems of radiated animals, and parts of 



