84 CLASS I.— ORDER II. 



SHINING. 



12. Sertularia splendens. Stem branching and 

 articulated ; two cells, alternate at each articulation ; 

 cells nearly cylindrical ; opening with three teeth, the 

 one on the external border much longer than the side 

 ones ; ovaria nearly cylindrical ; height from two to 

 four centimetres. 



Bay of Cadiz. 



SHRUBBY. 



1.3. Sertularia arhuscida. Root forming a large 

 base ; stem thick, short, and branching from its base ; 

 branches and shoots numerous, short, and scattered : 

 cells small, campanulated, bulging, and entire at 

 their border ; ovaria long and oval, with a small open- 

 ing at the summit ; colour deep brown ; height from 

 four to six centimetres. — Plate 5. fig. 4. a. B. C. 



Seas of Australasia. 



CYPRESS. 



14. Sertularia cupressina. Cells tubular and 

 adhering through all their length ; external border of 

 the opening higher than the inner. 



European seas. 



SILVER. 



15. Sertularia argentea. Cells pyriform ; branches 

 alternate and panicled. 



Seas of England and America. 



arbor vit^. 



16. Sertularia thuja. Cells in two rows and 



