BUCCAL MASS- 



Fig. 178. — Structure of the Ormer {Haliotis) 

 A, Shell from ahove, b, Semidiagrammatic view from above after removal of shell. The roof of the mantle-cavity 

 has been cut away and the heart exposed. The small left kidney (unshaded) and hinder part of large right kidney 

 (shaded) shown by transparency, c. Digestive organs, d, Diagram of nervous system. 



