82 A NATURAL HISTORY OF THE SEAS 



Polyzoa are distinctly coralline in appearance and like the 

 corallines are abundant everywhere, over 130 species 

 having been recorded from the coast of Devon alone. 



A typical Polyzoan consists of a large number of animals, 

 each an entity and occupying a horny or calcareous cell 

 yet joined to every other member of the community. The 

 colonies multiply by producing eggs which hatch into 

 larvae and eventually settle down and start fresh colonies. 



But here all analogy with the corallines ends. The 

 perfect animals instead of always being replicas of a set 

 pattern, like most polyps, often differ considerably in- 

 dividually. A normal member of a Polyzoa community 

 lives in a cell which is closed by a lid, having the wall 

 pierced with numerous holes through which the animal 

 keeps in connection with its fellows. The creature has a 

 crown of tentacles covered with hairs, which whirl minute 

 food particles into its mouth, instead of grasping food 

 in the manner of a polyp. 



As previously stated, the great majority suggest corallines 

 or seaweed growths. The Prickly Sea-mat (Vlustrella 

 hispida), with its wide flattened " leaves," is very common 

 on our eastern shores, whilst in the south the prevalent 

 species {Cellaria fistulosd) popularly known as Bugles 

 suggests masses of the once popular bugle beads. 



Membranipora, the Lacework Polyzoan, may be found 

 covering large areas of the common rock weeds with a 

 beautiful gossamer pattern. In striking contrast is the 

 Ross (Leprah'a joliarea) that forms huge stony masses 

 measuring at times seven or more feet across. Despite 

 its coralline appearance it is exceedingly brittle and as 

 washed ashore is of a dead white colour, but in life with 



