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CHAPTER VIII. 



FOSSIL SEA-MATS (POLYZOA). 



FEW people, possessed of natural history tastes, can 

 have examined the odds and ends thrown upon the 

 sea-beaches of the watering-places in the summer 

 without noticing that the larger seaweeds, and even 

 the bases of the numerous corallines, are matted or 

 encrusted with peculiarly lovely lace-like organisms, 

 which bleach to a pure white when dead. A magni- 

 fying glass shows clusters of cells, the residences of 

 tiny and relatively highly organized little creatures 

 which live together in a neighbourly fashion all of 

 them the descendants of an original ancestor, like the 

 "ham " of an early Saxon chief. The cells are variously 

 shaped, adorned or defended by spines, etc., so that 

 species can easily be multiplied. A good deal of 

 lime is employed in the walls and partitions of these 

 dwellings, hence their durability after death. Some 

 genera are remarkable for the relatively large quantity 

 of lime used in their common structure or Polyzoaria, 

 as, for instance, Eschara, etc. 



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