MOLLUSCA. 233 



cessary to the successful prosecution of the science of con- 

 chology. To accomplish this, much care and attention are 

 requisite. Shells must be sought for in their natural situa- 

 tions, and obtained, if possible, with the animal alive. After 

 the animal has remained dead in the shell for any length of 

 time, it loses its lustre and transparency, and becomes less 

 valuable, either as an object of beauty or curiosity. Hence 

 the collector must explore the sea-coast, the land, and the 

 fresh water, in search of the testaceous animals which they 

 support, for the purpose of obtaining in a perfect state their 

 calcareous coverings. 



The sea contains more species of shells than either the 

 land or the fresh waters, and presents to the conchologist an 

 extensive field for observation. Many species of marine 

 shells frequent the sea-shore, adhere to rocks, stones, or sea 

 weed, or lodge in the clay or sand. These are termed Lit- 

 toral shells, and are seldom found in deep water. The lit- 

 toral shells are easily collected at ebb tide. Those which 

 burrow in the mud or sand may be detected by a small de- 

 pression which they leave on the surface as they retire below 

 it. Other shells live in deeper water. To collect these the 

 dredge must be employed ; and if the shells be put into sea 

 water after they are brought up* the animals may afterwards 

 be examined with ease. Such collectors as have not the 

 advantage of a dredge, should examine the refuse of fishing 

 boats, and traverse the sea shore, and search the rejecta- 

 menta, especially after a storm of wind. The roots of the 

 larger JFuri, especially F. digitatus, which grows sometimes 

 in four or five fathoms water, frequently contain a treasure 

 of the rarer shells. 



During the ebb of stream tides, the conchologist ought 

 to be very diligent. The rocks are then uncovered, and 



