Curious Creatures 



213 



same thing. These odd creatures are also very beau- 

 tiful; their variegated colors and conspicuous corollate 

 gills give them the appearance of delicate flowers. A 

 constant circulation of the surrounding water is caused 

 by the cilia on the gill filaments, and these currents pro- 

 duce a vortex that brings oxygen to the gills, and small 

 organisms into its mouth. Serpula, departing from the 



THE MASON WORM. 



methods of the tube-building mason worm, which con- 

 structs its house of agglutinated shell and mineral frag- 

 ments, and the comb worm, which cements grains of 

 sand together in mosaic fashion to make its free cone- 

 shaped shelter, manufactures its ow^n materials. The 

 structure is a frail tenement, but one of imposing excel- 

 lence. It is a calcareous tube, winding about over small 

 stones or dead shells, and is, by some mysterious chem- 

 istry of the worm's body, converted from the com- 

 pounds of the sea. 



