PLATE XVI. 



have seen one of the white variety rather larger than any of the 

 brown colour that have occurred to our notice. . 



The shell we have selected for the figures in the annexed plate 

 is chosen rather for its extreme perfection than the superiority of 

 size ; we have observed it larger by nearly one half, but have not in 

 any instance met with one more entirely perfect : it is delineated from 

 the example of this very curious species in the late Leverian Museum. 



This species which for a century past or more has maintained 

 its reputation as a rare production is still held in much esteem, and 

 bears a price proportionately considerable : it inhabits the shores of 

 ISouthern Asia. Gmelin has the expression " Habitat pretiosus et 

 rams in mari, Asiam australem alluente, 4*c." and describes the 

 species as being either white, brown, or black. 



