CATECHISM OF CONCIIOLOGY. 63 



exudations that form their shells, and thus occa- 

 sions that exquisite variety in their testaceous 

 coverings, which art attempts to imitate, but can 

 never fully equal. 



CHAP. XXXIV. 



UNIVALVES: 

 HALIOTIS ; Sea Ear, or Ear Shell. 



Q. WILL you describe the Haliotis? 



A. The Haliotis is an open ear-shaped shell, 

 with a lateral and nearly hidden spire, in the 

 first division, longitudinally perforated with pores. 



Q. What is the signification of Haliotis ? 



A. It is derived from two Greek words, signi- 

 fying sea and ear, and is thus denominated on 

 account of its ear-like form. The animal is 

 attached by so adhesive a property to the surface 

 of the rocks, that it requires the utmost force to 

 disengage it, though by a spontaneous action it 

 is able to remove with facility from place to 

 place. 



F 2 



