242 MYTILUS. MUSSEL. Class VI. 



17. PLICA- Gm. Lin. 3358. Mont. Test. Br. Sup. 70. 



TUS. 



M. with a very thin pellucid rhomboidal shell, 

 slightly plaited and wrinkled, truncated on one 

 side close to the umbo; length less than half an 

 inch ; breadth double its length. 

 Isle of Sky. 



