PERIWINKLE. 



29 



and cerus — waxen. 'Botli the generic and specific names of 

 the second refer to the peculiar couforniation of the shell, 



CniXKSE SPINDLK. 



being derived from the Latin, and meaning a straight line or 

 beak. 



On Plate III, will be found the Imbricated Purpurea, {P. im- 

 hricata,) Fig. 1, which claims a close alliance vvith the Whelks. 

 Tlie generic name has reference to the dye yielded by this, as 

 well as all the shells of the genus; the specific name comes 

 from the Latin imbrex — the gutter-tile; thus imlricated, a term 

 often used in Natural History, means ridged, like the roof of 

 a house, where the tiles are placed to overlap each other, so 

 that the rain will run off. The Persian Purpura, or, as it is 

 called in Latin, Farpura Persica, Fig. 2, is another handsome 

 shell of this family group; its name indicates the place where 

 it is found. The other species described comes from South 

 America, and the P. lapillus, (the meaning of the specific name 

 has already been explained,) is common on our shores, being- 

 found in great abundance on the rocks at low w^ater. We read 

 in scripture, of Tyrian purple, and there is every reason to 

 suppose that the rich colour was obtained from these and other 

 sliell-fish. 



PEPtlWINKLE. 



This is the commonest representative w^hich we have of the 

 family Turlinidos, which comprehends, according 

 to Cuvier, all the species which have the shell 

 completely and regularly turhinated, that is, if 

 we translate the Latin word into English, twisted. 

 The little Periwinkle, (here lie is,) is by no means 

 a handsome mollusk, but some of his relatives 

 are very beautiful as we shall presently show. 



