iv - P 11 E F A C E. 



but also to arrange his collection by inspection, without 

 the trouble of consulting other publications on the sub- 

 ject. 



The plan followed in the present undertaking has been 

 to give one characteristic figure of each species, and the 

 arrangement adopted has been that of Linnaeus. The 

 Author is well aware that in this age of general novelty he 

 shall be censured by the young, and perhaps by the expe- 

 rienced conchologist, for adhering too tenaciously to the 

 principles of his early master ; but let it be remembered, 

 that all systems built on artificial foundations must be liable 

 to objection, and that it still remains to be proved whether 

 the present innovators had not better have trusted to the 

 Linnean method, with such additions and divisions as its 

 great author might be supposed to have made had he now 

 been living, than, by an extreme multiplication of the 

 genera, ratlier to increase than remove the difficulty of 

 determining the species. 



With a desire in some measure to accommodate those 

 who have adopted the French arrangement, the Author 

 has added the divisions of Lamarck, referring his genera 

 to the figures in the Index Testaceologicus. 



It may not be improper to remark that all the plates 

 (with the exception of the first six by that excellent artist 



