Handbook of Paleontology 143 



Sandy Bottoms 



The fauna of sandy beaches is composed largely of 

 animals that burrow and with this burrowing" ability 

 is often combined a heavy body. The surface of the 

 beaches, however, is strewn with remains of many 

 species, usually beach-worn, that are washed out of 

 the sands by the waves, some even carried in from 

 great depths and distances during storms. There will 

 be a great variety of mollusk shells, tests of crusta- 

 ceans, echinoderms, worms etc. As along rocky 

 beaches pelagic (swimming and floating) animals are 

 an important part of the fauna. Egg cases form an- 

 other class of objects to be looked for. There is the 

 Devil's Pocket Book, the egg case of the skate ; the 

 long strings of saucerlike capsules which are the eggs 

 of the Giant Whelks ; the collarlike sandy rings con- 

 taining the eggs of the Sand Collar Snail, which are 

 called Tommy-Cod Houses by the Cape Cod children ; 

 and the Ears of Corn which are cylindrical piles of 

 little capsules and are the eggs of the Ten-Ribbed 

 Snail. Along the upper part of the sand beach extends 

 an almost continuous belt composed of dead seaweed, 

 broken shells, fragments of crabs and lobsters and a 

 variety of debris cast up by the waves, and this sea- 

 wrack is alive with Beach Fleas and other small crus- 

 taceans. Variations in the fauna of sandy beaches de- 

 pend largely upon the purity of the sand and the pro- 

 portion of mud present. The slope of the beach is 

 also important as this affects the capacity for retaining 

 moisture. Plants, too, modify the sand faunas con- 

 siderably as there are many animals that live on the 

 blades or among the roots of plants. Just as with 

 the rocky shores, many zones may be recognized. 



