Handbook of Paleontology 139 



appendages (avicularia). In time of storm large quan- 

 tities of the Moss Animal are thrown upon the beach, 

 Another bryozoan, the Red Crust {Escharella variabilis) , 

 occurs on the rocks, as in the tide pools. There is only 

 one brachiopod or Lamp Shell that lives along our north- 

 ern coast, the Parchment Shell (Terebratulina septen- 

 trionalis) which ranges from Massachusetts to Nova 

 Scotia. Species of this genus are found in the shallower 

 waters of all seas. The animal lives from low tide to a 

 depth of 300 feet or more, and is extremely abundant on 

 rocky bottoms along the New England coast. The valves 

 of the shell are calcareous, about five-eighths of an inch 

 long, and there is a short fleshy pedicle attaching the ani- 

 mal to the rock. 



Echinoderms are well represented. Many of the sea 

 urchins, also called sea-eggs or egg-urchins, along coasts 

 exposed to the action of the waves, live in cavities which 

 they hollow out of the solid rock by mechanical action. 

 A form (Strongylocentrotus purpuratus) related to the 

 Green Sea Urchin occurs on the California coast in such 

 numbers that tracts of coast are completely honeycombed 

 and pitted with such burrows where the animals seek 

 shelter against the surf beating against the rocks. In 

 sheltered places the same species does not excavate. In 

 addition to the Green Sea Urchin we also have the 

 Purple Sea Urchin (Arbacia punctulatd) which ranges 

 along our coast from Mexico to Cape Cod. It is of a 

 dark brown or brownish purple color and is common on 

 broken rocky bottoms on rocks at low-water mark. The 

 Purple Sea Cucumber is found from Texas to Cape Cod. 

 The large purple form (Pentacta frondosa) is plentiful 

 along the New England coast, especially Maine. A form, 

 bright red in color (Lopholthuria fabricii Cuvieria squa- 



