INTRODUCTION. Vll. 



to the calcareciis nature of the rocks. Helix aperta 

 and Testacella haliotoidia have been found only in the 

 Channel Islands, and would, on that account, be erased 

 from the British fanna, by some naturalists. 



The implements required for carrying on the study 

 are few, simple, and not expensive. A spoon, for 

 scooping-up the water varieties from amongst aquatic 

 plants, which can be made of tin, with fine gauze 

 wire or perforated zinc at the bottom, the gauze must 

 be so fine that it will not allow the smaller Pisidia, 8^c. 

 to pass through ; to this a handle five or six feet in 

 length may be attached, or it is often convenient to 

 have it to fix on the end of a walking stick. Boxes, 

 of various sizes, to keep the finer varieties from being 

 broken, and to separate those found in difierent locali- 

 ties. "With these and a small Pocket Microscope, 

 the conchologist may consider himself fully equipped. 



After having collected a considerable number of 

 shells, our first care is to kill the mollusks which 

 inhabit them ; this is most speedily and efiiectually 

 accomplished by pouring boiling water upon them ; 

 we then disengage them by means of a needle, fastened 

 to a small handle, or perhaps occasionally use a crooked 

 pin. The very small ones need no cleaning. Our 

 next care should be to have them properly mounted : 

 this of course must depend almost entirely on the taste 

 of the collector. We have found a mahogany box or 

 case, eighteen inches square, and two inches in depth; 

 so made that the top and bottom are of equal depth, 

 the best suited for displaying the whole collection at 

 one view. The shells are attached by gum or glue 

 to the top as well as the bottom of the case. After 

 the inside has been papered out, the names, neatly 



