116 introductio:n to coxchology. 



and the variety of their decorations^ none are more \Yorthy 

 of admiration than the shells of this interesting genus. In 

 some, the varices are moulded into elaborate leaf-like fronds ; 

 in others are seen a succession of fimbriated laminae ; in 

 others, a row of long tubnlar spines ; in all, variations of 

 ornamental growth, which serve as characters for the sub- 

 divisions of the genus. The profuse enamelling of the 

 aperture is also very striking : the colours possess a purity 

 and brightness which no effort of the pencil can imitate. 

 Observe, for instance, the magnificent M. erytlirostoriia from 

 California and the 21. regius of Panama ; the first glowing 

 with the colours of the rainbow, the second uniting the 

 most brilliant colouring and elaborate structure. 



History relates that the Eomans obtained their celebrated 

 dye from the expressed juice of the Murex truncuhis, 

 inhabiting the Mediterranean and the shores of Tyre. The 

 M. hrandaris seems also to have been used for the same 

 purpose ; and M. Deshayes attempts to show that remains of 

 this species are still found in consolidated heaps upon the 

 coast, wa};-marks by which to distinguish ancient stations 

 for the extraction of purple. 



Tliis curious fact was ascertained during a scientific ex- 

 ]) edition to the Morea, when^ observing considerable heaps 



