MOLLUSKS. 



327 



ily, called the Royal Staircase Wentletrap. This is found 

 in the Chinese and Indian Seas. It is so costly- a fine 

 specimen commanding, even now, four or five pounds 

 sterling that the specific name attached to it is pretiosa, 

 precious. In the same figure is a specimen from the very 

 extensive Cone family. In Fig. 258 the large shell is that 



Fig. 258. 



of a Whelk, belonging to a family which, from the shape 

 of the shells, is called Buccinidae, from buccinum, a trum- 

 pet. The famous Tyrian purple was obtained from one 

 of this family. In the same figure is the little Cowry, 

 which is a current coin among the natives of Bengal, 

 Siam, and many parts of Africa. In Bengal, 3200 of 

 these shells are reckoned equal to a rupee, or about two 

 shillings of English money. In 1849 about three hund- 

 red tons of them were imported into Liverpool, designed 

 to be used in the African trade. One of the most beautiful 

 of the shells which are armed with spines is the Thorny 

 Woodcock, Fig. 259, sometimes called Venus' Comb. 



Fig. 259. Thorny Woodcock. 



