STUDIES IN MARINE ECOLOGY. 



221 



List 4. 



Showing Animals Found at Different Tide Levels on More 

 Exposed Rocks. 



A. At extreme high tide; NW. Gutter rocks. 



Orchestid agilis. 

 Talorchestia longicornis. 



B. At Half Tide; Same Place. 

 Ccelenterata : 



Sertularia pumila, much. 

 Crustacea 



Balanus balanoides, very abundant. 



C. Tide Pool among Rocks, Gansett. 

 Porifera 



Cliona celata. (?) 

 Microcione prolifera, some. 



Ccelenterata: 



Sagartia leucolena, few 



Bryozoa : 



Bugula turrita 



Annelida: 



Harmothoe imbricata, several. 



Hydroides hexagonus 



Leprcea rubra, few. 



Lepidonotus squamatus 



Spirorbis spirorbis. 

 Crustacea : 



Balanus balanoides, very many 



Mollusc a: 



Anomia ephippium, several small. 

 Acmea testudinalis 

 Cerithiopsis emersonii 

 Littorina litorea, very abundant. 

 Urosalpinx cinereus 



Chordata : 



Stylela partita 



15 



Mollusca: 



Mytilus edulis, several, small. 

 Littorina litorea, very many. 

 rudis, several. 

 palliata, some on 



Ascophyllum. 



D. Below Low Tide, Gansett. 



Ten times as much as in C. 

 Much, more than in C. 

 Leucosolenia botryoides, sev. colonies. 

 Grantia ciliata. 



Several 



Astrangia dance, sev. colonlies 

 Metridium dianthus, several. 

 Sertularia pumila. 



More here. 



Crissia eburnia, 1 colony. 



Several, more than in C. 



Many more than in C. 



Many. 



About same as C. 



Some 



Gammarus sp. many. 



Large ones here. 



More than in C. 



None. 



Fewer than in C. 



Many more than in C. 



Chcetopleura apiculata, few large. 



Anomia aculeata, several small. 



Modiolus modiolus, few. 



Crepidula plana, few. 



Littorina rudis, few. 



Few in both. 

 Amarcecium constellatum, much. 



