4 INTRODUCTION. 



under the appellation of " Vermes Testacea," without any 

 further notice of the animal, than an indication of the genus to 

 which it belongs ; thus the animal of Cypraea is said to be a 

 Limax, and that of Tellina a Tethys. 



The nearest approach to correctness, and the most philoso- 

 phical method of study will be found in the modern system, 

 adopted by Lamarck and his followers, of observing these 

 animals as a whole, and arranging them according to the 

 assemblage of characters which they present ; of course taking 

 into consideration the existence or non-existence, form and 

 structure of the shell, on the same principle, which, in 

 arranging the vertebrated animals would lead us to study the 

 hair, hoof, nails, claws, &c. as well as the other parts. 



At the same time, it must be admitted that there are many 

 private collectors of Shells who would find it a difficult, if not 

 impossible task to study minutely and successfully the soft 

 parts of the Mollusca. Ladies, for instance, could not be 

 expected to handle with pleasure and perseverance, these 

 fleshy substances, which in order to be preserved from putre- 

 faction, must be kept in spirits ; and yet such persons may, 

 with improvement and advantage to their own minds, enjoy 

 the interesting and scientific amusement of studying and 

 arranging the clean and beautiful natural objects which are so 

 easily preserved, and so exquisitely curious in their structure. 

 Let it also be remembered, that if shells had not been rendered 

 commercially valuable, by the zeal and emulation manifested 

 by mere Conchologists for the possession of rare specimens, 

 few travelling merchants and sea captains would have thought 

 them worthy of a corner in their cabins. In this case, few 

 specimens being brought to the country, the more Philosophical 

 Naturalist would have been left without the means of obtain^ 

 ing materials to work upon, or of attracting public attention to 

 his favourite pursuit. 



