210 COLLECTING SHELLS. 



would be very unwelcome guests in our house gardens^, as 

 they commit great havoc among the esculent plants. The 

 Achatina Zebra of Africa, is very frequently found seven 

 inches from the apex to the base. A few of our own land 

 shells are very beautiful ; but from their being familiar to 

 us, we look on them with the greatest indifference; for 

 example, Helices Pomatia, arbustorum, and nemoralis. 



Marine Shells are to be met with on almost every 

 shore in the known world, but those of warm climates have 

 in general a finer polish, and exceed all others in point of 

 colouring. 



Some authors affirm, that the Cypraea tribe abandon their 

 shells every year, to form new ones of a larger size ; but 

 this seems rather a doubtful circumstance, and has not yet 

 been satisfactorily explained. 



When shells are found with the animal alive, hot water 

 should be poured upon them. The animal may then be easily 

 taken from bivalve shells; but caution is required in the 

 univalves; as should part of it be left in the volutions, it 

 will be almost impossible to extract it; and the shell be- 

 comes very offensive. 



The instruments used in procuring marine shells are three, 

 namely, the Dredge, the Gangui, and the Rake. The latter 

 two are, however, not so important as the former, which we 

 shall first describe. 



OF THE DREDGE. 



There is no instrument like the dredge, in point of gen- 

 eral utility. It is much used for fishing oysters, and acts 

 upon the bottom of the sea almost like the rake. No natu- 

 ralist, who lives on the sea-coast, should be without a 

 dredge ; and to those travelling in foreign countries, in 

 search of natural objects, it will be found of the utmost 

 utility. It is to be much deplored that so few naturalists 

 think of possessing themselves of this very useful instru- 

 ment; as by its aid many remarkable animals might be dis- 



