STUDIES IN MARINE ECOLOGY. 229 



called for convenience the Cumingia association and in deeper 

 water and deeper muck, the region characterized by the annelid, 

 Scoloplos acutus, which may give its name to this association. 



On account of lack of time no water samples were taken over 

 the Cumingia grounds. Enough collecting to yield 25 Cumingia, 

 gave the following associates: 



Annelida: Poly cirrus eximeus, Trophonia affinis, Amphitrite 

 ornata, Glycera americana and Maldane elongata. 



Crustacea : Panopeus sayi. 



Mollusca: Tellina tenera, Solemia velum, Nucula proxima, 

 Venus mercenaria, Lcevicardium mortoni. 



Associated with these one usually finds the burrowing anemone, 

 Edwardsia elegans; the swimming annelid, Podarka obscura; the 

 shrimps: Palcemonetes, Crangon, and Hippolyte; and the green 

 crab, Carcinides. 



In both Northwest and Blind Gutters the Scoloplos acutus 

 association occupies several acres. At Gansett, the whole center 

 of the bay supports a dense growth of eel grass and from general 

 appearances, I should judge that it would belong to this associa- 

 tion but it comes out into . shallow water only in a relatively 

 narrow zone and there some of the typical animals, Thyone 

 briareus, for example, were not found. 



List 8. Showing the Common Animals Found on, among, and at the Roots 

 of Eel Grass in the Center of NW. and Blind Gutter Flats. 



A. On Eel Grass. 



Coelenterata : Crepidula fornicata (few). 



Sagartia lucice (frequently many). Littorina rudis (few). 



Bryozoa: Littorina litorea (many). 



Bugula turrita (much). Littorina palliata (few). 



Schizoporella unicornis (some) . Chordata : 



Gasteropoda: Molgula manhattensis (very few). 



Bittium alternatum (many). Botryllus schlosseri (little). 



Crepidula convexa (several) . 



B. Among Eel Grass. 

 Annelida: Crustacea: 



Podarka obscura (frequently abun- Virbius zostericola (very many) . 



dant) . M ollusca : 



Pecten irradians (.many). 



C. In Muck at Roots. 

 Echinoderma : Annelida : 



Thyone briareus (frequently abun- Scoloplos acutus (many), 



dant). 



