PURPURA. 



23 



a medium of exchange in some countries. Money 

 that can be picked up on the sea-shore is, how- 

 ever, of very small value, fifteen hundred cowries 

 being considered as an equivalent to one English 

 shilling — hardly reimbursing the collector for the 

 trouble of stooping so often. 



There is another shell allied or distinctly 

 related to the whelk which is very common on 

 our coasts, and which is well worthy of notice. 

 This is the Furpura lapillus (plate b, fig. 4), a 

 shell that is sometimes found nearly white, but 

 mostly banded with brownish orange, as is repre- 

 sented in the figure. Now, the creature that 

 inhabits this shell is one of those animals that 

 furnished the famous purple of the ancients, and 

 from that property it derives its name of Purpura. 

 The colour is not particularly beautiful, and it 

 is rather remarkable that the ancients, who had 

 very good taste in colours, should have placed so 

 high a value on this purple, which, according to 

 their own account and our observations, closely 

 resembled clotted blood. 



Perhaps, however, its rarity constituted its 

 value ; for there is so little in each shell, that an 

 enormous number of victims must have perished 

 before a sufficiency of the dye for one robe could 

 <have been obtained. 



