CYPR.EA. BULLA. 31 



dermis ; but will bear a brilliant polish. C. te.v- 

 tilis, cloth of gold, is valuable. C. generalis is 

 sometimes sold for twenty guineas. The example 

 on the table is C. EhrcEus, or Hebrew cone. 

 (Plate 6.) Species one hundred and fifty-five ; 

 not one British. The greater number are 

 brought from the Indian Ocean ; some from the 

 seas of Africa and from the South Sea. 



" The shells of the genus CyprcBa, cowry, are 

 general favourites : the species are fifty-eight ; 

 one British, C. pediculus. C. moneta (Plate 

 1) is very common. The generic characters are, 

 shell univalve, involute, obtuse, smooth; aperture 

 linear, the whole length of the shell ; effuse at 

 both ends, toothed on each side. 



" Look carefully at those three shells : do you 

 perceive much resemblance between them ? 

 * Not much, if any,' you reply, yet they are all 

 of the genus Bulla. Here is B, Ugnariay B. 

 terehellum^ (see Frontispiece,) andB.naucum, 

 (Pate 6.) There are other forms, as the B. ovum, 

 B. volva, the firsftisomewhat like a cowry ; but it 

 is toothed only on one side of the aperture ; the 

 second has two long beaks. 



" This genus is confessedly ill-determined. 

 B. naucum and B. ampulla are examples of the 

 common characters of the genus. The species 

 are sixty-one. 



'* Voluta is also a large genus, containing one 



