MOLLUSCS. 103 



to have considerable influence in the preparation of exactly the right shade 

 of color. The species employed were Murex brandaris, Murex trunculus, 

 and Purpura patula. 



These shells were gathered in enormous quantities and broken in the 

 stone mortars already mentioned. To the mass thus obtained soda was 

 added, and then sea-water. At first the liquid was yellow, but under 

 exposure to the sun and atmosphere it slowly changed until a purple color 

 was assumed, the change being accompanied by the production of an odor 

 much like that of assafcetida. When the purple color of the liquid was 

 obtained, it was ready for dyeing ; and wool dipped in it for a few 

 hours would be indelibly colored. Some of the shades of color were very 

 cheap, but others brought enormous prices, a slight difference in shade 

 being frequently worth a great deal. Indeed, wool d}*ed one particular 

 shade was enhanced one hundred times in value, while if not exactly that 

 color was obtained, the increase in value by dyeing would not be a tenth 

 as much. 



Murex brandaris, one of the species just referred to, causes great 

 damage to the shell-fisheries in Europe, and an allied form, the drill 

 (Urosalpinx), is a pest on our own shores. The drill is but an inch in 

 length, and yet the oyster succumbs to it. It settles down upon the 

 oyster, and begins to bore through the shell. The boring-tool is the 

 lingual ribbon described above, its sharp teeth cutting through the shell 

 quite rapidly. Slowly but surely the shell is cut away, the hole produced 

 being round and as neatly countersunk as if a mechanic had finished it. 

 At last the shell is punctured, and the oyster falls a victim to its much 

 smaller enemy. Many others of the predaceous molluscs bore through the. 

 shells of their fellows in exactly the same way as does the drill : and a 

 casual walk along the sea-shore will show many shells bored and counter- 

 sunk, which can thus be recognized as the remains of some molluscan 

 dinner. 



Our American purple shells {Purpura) are very common, and all secrete 

 the same yellow fluid, which changes to purple ; but no use is made of it 

 now. Modern chemistry has produced colors from coal tar which are fully 

 as brilliant as any produced by either the animal or vegetable world, and 

 far cheaper than they. They may not be so permanent; but this matters 

 little, for most of them will outlast the fabric colored by them. 



The cones (Conus) have a shape well indicated by their common and 

 scientific names. All the species are tropical or sub-tropical, the eastern 

 •seas being the home of the great majority of them. Their shapes and 

 bright colors have long made them favorites with collectors, and in all 

 museums the visitor will find large series of them. They also have another 



