MOLLUSC A OR UNIVALVES. 259 



with the most beautiful and extraordinary 

 figures, some of them resembling Hebrew, 

 Greek, or Arabic characters, and bearing a 

 most exquisite polish ; in other varieties the 

 colours are arranged in almost endless shapes, 

 being clouded, veined, marbled, dotted, striped, 

 and banded, in every kind of form. Many of 

 them are very rare, and a specimen of the Conus 

 gloria maris has been sold for as much as one 

 hundred guineas.* 



In some of the species the spire presents the 

 appearance of having been pushed into the body 

 of the shell, the apex being below the level of 

 the outer whorl ; a spire of this kind is called 

 retuse. 



When a section is made of a cone, it will 

 appear that the sides of the internal whorls are 

 much thinner than those of the external ; it is 

 supposed that this arises from the animal re- 



* The famous Conus cedo-nulli, formerly in the cabinet 

 of Lyonnet, at the Hague, is said to have been sold for 

 three hundred guineas. There are very few specimens 

 existing. Lamarck's specimen was considered by him 

 the most precious in his collection. 



s 2 



