CHAPTER XIX: THE CONCH SHELLS 

 Family Strombid/^ 



Shell heavy, porcellanous, with conical spire; aperture 

 elongated, channeled at both ends; outer lip generally thickened 

 and dilated; curved sinus for the head near basal canal; oper- 

 culum claw-like, horny, notched on edge; foot narrow in front, 

 arched and broad behind; head with contractile snout, highly 

 developed eyes' tentacles rising from stout eye-stalks; radula 

 well developed; siphon short. 



Active, intelligent mollusks, chiefly carrion-feeders, found 

 on reefs in tropical seas. Shells used in manufacture of porcelain 

 and lime, in cameo-cutting and for ornament. Animal sometimes 

 eaten. 



THE TYPICAL CONCHS 



Genus STROMBUS, Linn. 



Shell ovate, solid, usually tubercled, lip dilated only when 

 full grown, polished within. About sixty-five species, chiefly 

 of large size, represented in Florida by a few West Indian species. 



The Queen Conch (S. gigas, Linn.) is the largest mollusk 

 native to any part of this country. It ranks with the giant shells 

 anywhere, indeed, for it occasionally measures a foot in length, 

 and attains a weight of five pounds. Moreover, it is a handsome 

 shell, for its horny, rough exterior has polished rosy lips and 

 lining. Valuable pink pearls are sometimes found within the 

 mantle folds, though they are but semi-precious, being china- 

 Hke in texture rather than pearly. 



The pink outer layer of the lip has a white foundation, and is 

 used by cameo-cutters. Shells which give greater colour contrast 

 between the raised figure and its background are preferred in the 

 cameo trade. The pink fades by exposure to light in both pearls 

 and cameos. In spite of these faults conch shells are much used. 



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