A-2, 



The zonation of epifauna on the continental margins is 

 a relatively new field of interest. In a study of the 

 isopod fauna on the continental margin off Cape Hatteras, 

 Menzies, George and Rowe (1973) found three major faunal 

 zones. Their study identified a shelf faunal province 

 extending to a depth of approximately 246 meters, which is 

 slightly below the shelf break. On the upper continental 

 slope (445-940 m) they found a zone of faunal transition 

 between the shelf and abyssal faunal constituents. This 

 zone is known as the archibenthal zone of transition and is 

 characterized by a gradual replacement of fauna along 

 isobaths (Markle and Musich, 1974) . The deeper abyssal 

 faunal province includes the lower portion of the continen- 

 tal slope, the rise and the abyss (1000-5315 m) . This zone 

 is occupied by fauna with broad depth ranges and may be 

 further subdivided into upper and lower assemblages. Two 

 major faunal boundaries were identified, the upper one just 

 below the shelf break and the lower one in the region between 

 the upper and lower portions of the slope. 



In a study of the epifaunal of the continental slope 

 south of Cape Cod, Haedrich, Rowe and Polloni (1975) found 

 three similar faunal zones with the two major boundaries at 

 300-400 m and 1000-1100 m. The authors correlate these 

 boundaries with changes in substate type, sedimentation rate 

 and gradient of the slope. The shallow faunal boundary 



