HALF AN HOUR WITH CORALLINES. 



91 



name is well given to it, for it does not require any 

 effort of the imagination to see in it the likeness of 

 a fir tree. Hence it is named the "sea-fir" par 

 parenthese, and this has been extended to all the 

 Sertularians, whence their popular generic name. 

 It has a slightly waving stem (Fig. 42), with branches 

 on each side. Its height is usually seven or eight 



Fig. 40. 



Fig. 41. 



Sickle Coralline, magnified. 



Hydrallmannia falcata, magnified. 

 a. capsule. 



inches, sometimes more, and its breadth across the 

 branches about three. The latter are usually shorter 

 towards the apex. Both along each side of the stem 

 and branches every available spot is occupied with 

 cells, each enclosing a separate animal when alive. 

 These cells, or calycles, are large and flask-shaped 

 (Fig 43), having their mouths turned outwards and 



