CHAPTER IV: THE PURPLES. DOG WINKLES 



Family Muricid.^ 



Sub-family PURPURINiE 



Shell bears nodules but no varices; columella flattened, 

 spread out; canal short, or a mere notch; operculum oblong, 

 with lateral nucleus. A large sub-family whose boundaries can- 

 not be definitely set at present. 



Genus PURPURA, Brug. 



Shell oblong-oval, last whorl large; spire short; aperture 

 large, ovate, ending in short, oblique canal or notch; columella 

 flattened; outer lip simple; operculum horny. 



A carnivorous genus, living from the water line to twenty- 

 five fathoms' depth in all parts of the world. Recent species, 

 fifty-seven; fossil species, forty. Tertiary. 



By the recession of the tide these mollusks are left out of 

 water twice a day for several hours. They breathe air which 

 passes over a small quantity of water retained in the branchial 

 cavity. They are amphibious, as well as carnivorous; and well 

 protected by their strong shells against injury by the waves and 

 by predatory birds and mollusks. Altogether, they are adapted 

 to succeed in the race for life. 



The common name of this genus has a long and interesting 

 pedigree, which takes us far back into ancient history. The 

 "Tyrian purple," famous because used solely for dyeing garments 

 to be worn by emperors and kings, was obtained by crushing 

 these mollusks in mortars or in pot holes along the rocky coasts 

 of Tyre and other Mediterranean ports. Pliny says that 1 1 1 Pur- 

 puras to 200 Buccina, pounded together, produced the richest 

 shade of purple. The animals of large species were removed 

 from their shells. 



The colouring matter is not contained in the shell, but in a 



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