From "Animal Lije by the Sea-shore" (Country Life). 



"THE ABUNDANCE OF LIFE." 



Acorn-shells or rock-barnacles. These sedentary crustaceans cover the rocks and are exposed at low tide. When the tide 

 is in they waft food-particles into their mouths by means of six pairs of curl-like limbs. When the tide is out they close the four 

 valves which form the roof of each rampart-like shell. Huxley spoke of them as fixed by their heads, kicking their food into 

 their mouths with their legs. The larvae swim freely in the sea. 



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Photo: J. J. Ward. 



A GROUP OF DIATOM SHIELDS. 



There is a great multitude of life in the sea. The above illustration shows the 

 variety of Diatom shields; these are the siliceous skeletons of minute unicellular 

 plants. The group in actual size, arranged in a circle, is only % of an inch in 

 diameter. At the autumnal climax of productivity in lakes there may be to the 

 square yard 7,000 millions of one well-known Diatom. 



