Star'fishes, Sea-urchins, etc. 



753 



1 1 \CK 'sLi n CT MPI I 

 This photograph was taken through the water in a coral-pool. A large clam-shell, with its expanded fringe of tentacles, is close beside the sea-cucumber. 



comparatively deep water that the dredge may be filled with a tangled mass of their writhing 

 snake-armed bodies. Should it be night when the dredge is brought aboard, and its contents 

 are emptied upon the deck, the spectacle presented as the star-fishes scramble in all direc- 

 tions, their bodies and arms aglow with jjale green or blue phosphoric coruscations, is highly 

 remarkable. 



CHAPTER IV. 



MOSS-ANIMALS. 



A LITTLE grouj^ of animals whose relationship with the sub-divisions previously and 

 hereafter described cannot be very definitely determined is that of the jMoss-animals, 

 sometimes designated Corallines, or Lace-coeals. All its members are of exceedingly 

 minute size, and if living separately would be scarcely discernible to the unaided vision. 

 They are, however, in the habit of forming stocks, or colonies, after the manner of corals, 

 by a process of continual budding, and in this way build up social aggregations which may 

 be of considerable dimensions. The majority are marine, and largely in evidence on almost 

 every seashore in the form of the so-called Sea-mats, consisting of masses of minute, light 

 brown, horny cells, which take the form of seaweeds, or are spread in thin, lace-like 

 encrustations upon the surfaces of shells, stones, and the larger seaweeds. The living 

 inhabitants of these cells are as transparent as glass, their most characteristic feature being 

 the elegant shuttle-cock-shaped crown of tentacles which is thrust out or withdrawn at will 

 from the aperture of each tiny tenement. The assistance of the microscope is requisite for 

 the apprehension of these details, as also of the somewhat complex alimentary and other 

 organs enclosed within the component cells. 



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