that the hydroid was not the cause of the 

 heavy natural mortality of scallops. 



LITERATURE CITED 



AuRiviLLius, Carl W. S. 



1891. Uber Symbiose als Grund accessorisches 

 Bildungen bei niarinen Gastropodengehausen. 

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 Balss, H. 



1924. Uber Anpassunger and Symbiose der 

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 Bunting, Martha. 



1894. The origin of sex-cells in Hydractinia and 

 Podocorync; and the development of Hydractinia. 

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 Dales, R. Phillips. 



1957. The interrelation of organisms. A. Com- 

 mensalism. Geol. Soc. Amer., Memoir 67, 1: 

 391-412. 

 Fraser, C. McLean. 



1944. Hydroids of the Atlantic Coast of North 

 America. Univ. Toronto Press, Toronto, 451 pp. 

 Hargitt, Chas. W. 



1908. Notes on a few coelenterates of Woods Hole. 

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 Merrill, Arthur S. 



1961. Some observations on the growth and sur- 

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 1961, Bull. 28: 4-5. 



1964. Observations on adverse relations between 

 the hydroid, Hydractinia echinata, and certain 

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 Merrill, Arthur S., and J. A. Posgay. 



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Moore, Hilary B. 



1937. Marine fauna of the Isle of Man. Proc. 

 Trans. Liverpool Biol. Soc. 50: 1-293. 



Odum, Eugene P. 



1953. Fundamentals of ecology. W. B. Saunders 

 Company, Philadelphia, 384 pp. 



SCHIJFSMA, KAATJE. 



1935. Observations on Hydractinia echinata 



(Flem.) and Eupaguriis bernhardus (L.). Arch. 



Neerl. Zool. 1: 261-314. 

 1939. Preliminary notes on early stages in the 



growth of colonies of Hydractinia echinata 



(Flem.). Arch. Neerl. Zool. 4: 93-102. 

 Sumner, Francis B., Raymond C. Osburn, and 

 Leon J. Cole. 



1913. A biological survey of the waters of Woods 



Hole and vicinity. Bull. [U.S.] Bur. Fish. 31: 



547-794. 

 Wells, Harry W., and Mary Jane Wells. 



1964. The calico scallop community in North 



Carolina. Bull. Mar. Sci. Gulf Carib. 14: 



561-593. 



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