AN 



INTRODUCTION 



TO 



CONCHOLOGY; 



OR, ELEMENTS OF 



THE NATURAL HISTORY OF 



MOLLUSCOUS ANIMALS. 



BY 



GEORGE JOHNSTON, M.D., LL.D., 



.. 



FELLOW OF THE ROYAL COLLEGE OF SURGEONS OF EDINBURGH. 



LONDON: 



JOHN VAN VOORST, PATERNOSTER ROW. 



M.D.CCCL. 



