MOLLUSCA OR UNIVALVES. 197 



and those of Ireland, (in consequence of the 

 gulf stream and westward winds,) and in the 

 European seas ; the other, «7. globosa, is from 

 Madagascar, the tropical seas, and the Medi- 

 terranean. They are seen floating on the sea, 

 suspended by the foot, from which a violet- 

 coloured liquid is emitted when the animal 

 is touched or injured. The shell is so ex- 

 tremely brittle that it is seldom met with 

 unbroken. Sir Everard Home states that the 

 animal carries its eggs on its shell for some 

 time. 



Family 7. — Macrostomidce* 



The Macrostomida are of a very simple con- 

 struction as far as regards the shell : the spire 

 is small; so much so, indeed, that the mouth of 

 the shell is nearly as large as the shell itself. 

 They are usually highly iridescent in the inside, 

 and have no operculum. They are all marine, 

 and are divided into four genera. 

 9 64. Sigaretus. — Shell ear-shaped, not 



* Les Macrostomes, Lamarck. 



o 3 



