GASTEROPODA. 



53 



colours on their internal surface. They are often known 

 by the common names of spider or scorpion shells. 



Strombus. Lin. — Shell thick and oval ; spire mo- 

 derate ; mouth long, and rather narrow, ter- 

 minated by a canal more or less long and 

 recurved ; right lip dilated in the adult, and 

 having a small notch or sinus near the canal ; 

 left lip sometimes thickened ; operculum 

 horny, long and narrow. Animal, the 

 tongue has an upper broad convex tooth in 

 the middle, with seven notches, the side teeth Strombus lobatus. 

 are divided into three points, the two outer of which are 

 simple hooks ; eyes very large ; the other parts of the 

 animal are exactly described in that of the family. — 56 

 species * ; also fossil. 



These shells are brought from India, Africa, and other 

 tropical countries, where they are found on reefs at low 

 water. Many of them attain a large size ; and the 

 Strombus gigas, called the fountain shell in the West 

 Indies, is used for the purpose of paving the streets at 

 Santa Cruz and elsewhere ; great numbers are also brought 

 to Europe for the manufacture of cameos. The spire in 

 many species is hidden by the expansion of the outer lip ; 

 the latter is sometimes reflected inwards, towards the 

 middle part. 



The animals of the Strombus occasionally produce 

 pearls. Mr. Wood, in his " Zoography," relates that he 

 saw a pink pearl which was taken from the body of the 

 animal of the Strombus gigas, which is caught for the 

 table off the island of Barbadoes. The pearl was dis- 

 covered by chance, whilst the men were employed in clean- 

 ing the mollusc. Its weight w r as 24 grains ; but it would 



* Reeve's Iconica. 

 e 3 



