vi ADVERTISEMENT. 



to the second shell figured by Koninck ; the fossil seems to me congeneric with tliose ecarinate 

 Pleurotomarice, for wliich I have proposed the name Platijschisma ; its affinity to Solarium is 

 certainly more remote. Pleurotomaria Hainesii of this work should be changed to Pleuroto- 

 maria naticoides, De Kon., the species being identical. And finally, the Producta tortilis of 

 this Synopsis is figured by Koninck as the Productus undatus, Defrance. 



In drawing attention to those corrections which have arisen from the almost simultaneous 

 discovery by M. de Koninck and myself, of a few species, I must express a hope, that I have 

 not similarly erred with regard to any other authors, either by overlooking or misunderstanding 

 their descriptions; no one, at least, can be more anxious to avoid such errors, or to correct 

 them, when in my power. 



FREDERICK M'COY. 



