118 New York State Museum 



various types of shore also differ somewhat on the 

 open coast from those in bays and estuaries, although 

 the general character of the assemblages is the same. 

 Besides the above, there are other types of associations 

 to be considered, such as the life of the brackish waters 

 in estuaries, harbors and marshes ; the life of wharves, 

 piles etc. ; the life of reefs, the life of shelly bottoms 

 etc. It would be out of the question and also not fit- 

 ting to take up in this chapter a detailed and complete 

 discussion of all the types of plant and animal asso- 

 ciations. It is proposed to give here mainly a picture 

 of the assemblages of life characteristic of each of the 

 three main types of shore, rocky, sandy and muddy, 

 so that the beginner in studying our geologic formations 

 with their fossil content may have some idea of the 

 conditions under which the life of those ancient times 

 existed. Also, emphasis will be placed upon the life 

 of our Atlantic coast, particularly the northern shore, 

 noting, however, where there is a particularly long 

 range. 



Rocky Shores 



The vegetation of the sea is definitely limited to the 

 surface (plankton) and the shallow waters and is quite 

 conspicuous at the strand, between tides. Seaweeds find 

 places of attachment along rocky shores and they, as well 

 as the crevices of the rock, afford shelter to many ani- 

 mals that could not live in more open and exposed places. 

 The Rockweeds (Fucus nodosus, F. vesicidosus) occur 

 from near low-water mark of ordinary tides to nearly 

 half tide, and they form large beds of vegetation very 

 conspicuous on our rocky shores when the tide is out. 

 Above the Fucus zone another brown seaweed (Asco- 



