142 New York State Museum 



rocky shores is replaced on the rocks of the west 

 coast by another species (Mytilus calif ornicus) which is 

 about the same size. The Cod Clam (Cardita boreal is) 

 which forms one of the foods of the cod is common on 

 rocky and gravelly bottoms at depths of 30 to 600 feet 

 and is found from Cape Hatteras to the Arctic, on the 

 Pacific shores of Alaska and on the northern coasts 

 of Europe. The shell is covered with a dark brown 

 skin and is about one inch long and three-quarters of 

 an inch wide and has 20 deep curved furrows radiating 

 out from the beak. There are two interesting rock- 

 boring bivalves found on our Atlantic coast. The 

 Angel's Wings (Pholas costata) ranges from Cape 

 Cod to South America, but is not abundant north of 

 Hatteras. The shell is seven or eight inches long, 

 white in color, and the suggestive shape and ribbed 

 sculpturing give it the name. It is found in holes 

 gouged out of solid rock which the animal makes by 

 constantly turning the shell around. It also makes 

 holes in. wood and sometimes in hard clay like Petri- 

 cola. In Florida it burrows deep in sand as well as 

 in wood or rock. The other rock-boring forms (Litho- 

 phagus) are common in tropical oceans. They are 

 found in the coral rocks of Florida. The animal when 

 young bores or dissolves out a cavity within coral 

 rocks or dead coral and remains there the rest of its 

 life, enlarging the cavity as it grows. 



The above summary covers the common, more 

 readily recognized forms of our rocky shores. There 

 will be found on these shores also many forms that 

 live in deeper water and are washed in during storms. 



