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LXXI. An alphabetical Afrangement of the Places, from 

 'whence the Fossil Shells har^e been ohtaincel, ii-hich are 

 engraved, coloured and described, by Messrs. Soivetiby, in 

 Vol. IV. o/' their " Mineral Conchology," ivith the geo- 

 graphical and stratigraphical Situations of the Places, and 

 the Species of Fossil Shells, ^r. Bj/ Mr. John Farey, 



Mineral Surveyor. 



To the Editors of the Philosophical Magazine and Journal. 



Howland-street, May 5, 1823, 

 TN your 46th, 52d, and 59th vokimes are inserted, alpha- 

 -*■ betical Lists of the Places mentioned by Mr, Sowerb}^, or 

 by those Authors to whom liis synonyms refer, as localities 

 of the Fossil Shells figured and described, in the three first 

 volumes of his " INIineral Conchology." the fourth volume of 

 this important monthly Work was completed on the 1st inst., 

 and I hasten to send 3'ou a similar List, of Places mentioned 

 in this last volume. 



The Genera of Shells are 46 in number, and the Species 

 named are 148, which this volume describes, besides four va- 

 rieties which Mr. Sowerby has distinguished by ^. In addition 

 to which, I have deemed it probable, that 12 other varieties*, 

 might usefully be distinguished from those he has named, on 

 account, as well of their belonging to other Strata than those 

 named, as on account of slight, but constant and invariable 

 differences which, as I believe, these resembling Shells of dif- 

 ferent Strata present, for distinguishing those of each stratum, 

 respectively : and I have accordingly, as before, made these 

 stratigraphical distinctions, by means of /3, y, or 8, &c. added 

 to the Name, so as to distinguish, in the whole, in the strati- 

 graphical Index to this volume, 160 species (or varieties) be- 

 longing to distinct Strata, 



In your 45th volume, p, 274, and your 53d volume, p. 112, 

 I have taken a review, of the chief circumstances which at- 

 tend the stratigraphical distribution of Fossil Shells; and have 

 in the latter paper endeavoured to call the attention of col- 

 lectors and conchologists, to the minuter differences which di- 

 stinguish certain muUistratular Shells from each other, although 

 passing at present, under the same specific name: concluding 

 with a List, the result of considerable labour and research, of 



* The species of these are, Ammonites Parkiiisoni 2 varieties, Gryphaea 

 cohiiiiba 1, Nerita eoncava 1, Patella striata 1, Pinna tctragona 1, Pro- 

 (hictus lobatiis 1, P. Martini 1, Rostelhiria I'arkinsoni 3, and Tcrcliratiila 

 rcsiipinata 1 variety. 



all 



