PREFACE. IX 



at Parma, where I studied, in the cabinets of Signer 

 Guidotti, a beautiful collection of Italian tertiary 

 shells, consisting of more than 1000 species, many 

 of which had been identified with living testacea. 

 Signor Guidotti had not examined his fossils with 

 reference to their bearing on geological questions, 

 but computed, on a loose estimate, that there were 

 about 30 per cent, of living species in the Subapennine 

 beds. I then visited Florence, Sienna, and Rame, 

 and the results of my inquiries respecting the ter- 

 tiary strata of those territories will be found partly in 

 the body of the work, and partly in the catalogues 

 given in Appendix II. 



On my arrival at Naples I became acquainted with 

 Signor O. G. Costa, who had examined the fossil 

 shells of Otranto and Calabria, and had collected 

 many recent testacea from the seas surrounding the 

 Calabrian coasts. His comparison of the fossil and 

 living species had led him to a very different result 

 in regard to the southern extremity of Italy, from that 

 to which Signors Guidotti and Bonelli had arrived in 

 regard to the north, for he was of opinion that few of 

 the tertiary shells were of extinct species. In con- 

 firmation of this view, he showed me a suite of fossil 

 shells from the territory of Otranto, in which nearly 

 all the species were recent. 



In October, 1828, I examined Ischia, and obtained 

 from the strata of that island the fossil shells named 

 in Appendix II. ; p. 57. They were all, with two or 



