90 



SEA AND LAND 



beneath the ocean while other parts are extended farther into 

 the field of waters, these L^reat lands are never deeply sub- 

 mero-ed, and that correspondingly the abysmal realms are 

 never converted into dry land. This view finds much sup- 

 ■ port in the fact that each of the continental 

 areas has a somewhat peculiar assemblage of 

 life which is evidently continued in unbroken 

 succession throughout the greater part of the 

 time which is recorded in the pages of the 

 great stone book whose leaves are the strata of 

 the successive formations. As the i)ast is the 

 index to the future, we may anticipate in the 

 hereafter of this ancient though still youthful 

 sphere, that geographers will often have to 

 reframe the charts of land and sea, but it is 

 doubtful if they will ever delineate as con- 

 tinents those portions of the world which are 

 now in the deeper parts of the ocean. 



We have now considered the principal topo- 



Showing at the top 



the arms which graphic featuTcs of the sea-floors, and have 



branch from the ca- 

 lyx which encloses notecl the fact that they consist mainly of 



the body caviiy, and 



at the base the root- extcusivo plaiuswith geutlo slopes toward the 



like processes whicli 



attach it to the bot deep Water extending for some distance from 



torn. 



the shore, and terminating in steeper slopes 

 which lead down into deeper water ; broad undulating fields 

 in tlie bottoms of abysmal depths; volcanic peaks generally 

 grouped in long ranges ; and lastly the shore walls and steep 

 cap-topped cones of the coral reefs or isles. We will there- 

 fore turn our attention ta the organic forms which people 

 this vast realm — forms so numerous and varied, that we can 

 only consider their more important aspects, limiting ourselves 



Living Crinoid. 



