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 (Cypre@a 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superseded by blankets.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 Arca granosa, the 
red from Chama Pacifica, 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 
