142 THE LIFE OF THE MOLLUSCA 



Italy, was the headquarters of this quondam 

 industry. 



In some quarters of the globe shells serve the 

 purpose of money. Of these the best known is the 

 Money Cowry (Cyprcza moneta), which used to pass 

 for currency in India, and is still largely used in 

 West Africa. Among the tribes of North-Western 

 America a species of Dentalium was employed till 

 superseded by blankets. On the eastern coast of 

 North America, " wampum " was long the medium 

 of exchange : it was formed of beads made by grind- 

 ing down the Common Clam ( Venus mercenaria). 

 Another form of wampum, made from Saxidomus 

 and Haliotis, was current in California, while in 

 Benguella the same sort of money was manufactured 

 out of a Land Snail (Achatina monetaria). 



In New Britain the native shell-money, or 

 " diwara," consists of shells of Nassa callosa, bleached, 

 perforated by knocking off the curious hump, and 

 threading them on rattan slips. 



Besides these there is the shell-bead-money, gener- 

 ally known as " rongo," of Malaita, in the Solomon 

 Islands, which is of three colours — white, red, and 

 black. The white is made from Area granosa, the 

 red from Chama Paciftca, and the black from a black 

 Mussel, or Pinna. 



More quaint was the custom prevalent at one time 

 on the west coast of Scotland, whereby, when a 

 bargain was struck, each of the parties kept one-half 



