90 On the Land and Fresh-waier Shells of Wills. 



give the large number above. The old Roman snail (Helix Po- 

 matia) has 21,000. The common Water Snail sold in London as 

 the Scavenger Snail, has upwards of 12,000 ; these are all arranged 

 in rows at right angles to each other, but this arrangement is not 

 invariable, the Testacella has a most superb palate fringed with 

 barbed teeth : remarks will be made about this slug and the 

 Roman snail presently. Some persons may feel anxious to be 

 instructed as to the utensils necessary for collecting shells. My 

 plan is very simple : for all water shells, I use an ordinary tin 

 strainer or colander of small size, such as would be purchased for 

 a few pence, and would be used for straining infants' food, or pearl 

 barley : the handle of this is knocked out, and through the hole 

 which will generally be found in it, or a hole purposely made, I 

 fasten a string. This apparatus will very easily go into a coat 

 pocket. I have also a walking stick, the bottom of which just fits 

 the cavity caused by the handle being knocked out of the colander : 

 just above the ferrule of the stick is a hole made by a gimlet, 

 through which the string fastened on the strainer is made to pass : 

 the object of course will be seen at once : it is to fasten the colander 

 80 that it shall not be lost. Equipped then with these two articles 

 and plentifully supplied with wide mouthed bottles, tin boxes, and 

 perhaps a fishing can, I am ready to search in the ditches for the 

 minute bivalves, and in the larger streams and canals for various 

 creatures, of various sorts. 



For land shells, boxes only are needed, combined with good use 

 of eye-sight, climbing powers, good ability for walking, with some 

 slight knowledge as to proper places to detect the habitats, a know- 

 ledge readily acquired by examining any work upon the subject, 

 or even slightly gained by reading the list of localities intended to 

 be attached to a future supplement of this paper. 



When shells are obtained, they can either be made of service for 

 the cabinet or for an aquarium. If for the former, let them be 

 put in a vessel and pour boiling water upon them : but, pray take 

 care, in order to secure the speedy death of your victims that the 

 water is thoroughly boiling: it is well to use a little salt in addition 

 for the larger sorts. When the creatures are dead they may be 



