processes reveal the presence of this delicate "crust" (fig. 17). Nemertean worms feed 

 across the surface of the sea floor while a portion of their bodies remains embedded 

 in the sediments (fig. 18). 



The abundance of holes in the area visited suggests that there is probably a consid- 

 erable overturn in the sea-floor sediments, primarily by animals. Very low mounds, 1 

 to 2 inches high, with diameters of about 2 feet appeared to be spread-out cones, 

 originally erected by burrowing animals but subsequently modified and smoothed out 

 (fig. 10, 12). Although no animals were seen to occupy these holes in the deeper waters, 

 it is a reasonable inference that they are formed by worms. Sediment discharged to the 

 surface by biological activity to form small volcano-shaped mounds was greyer than 

 the surface layer. Clay-silt samples taken with a gravity corer from a surface vessel 

 revealed that such grey sediments normally occur several inches below the surface. 



On a dive to 2800 meters, dune-like formations of great magnitude were seen (fig. 

 14). These elongated ridges had a crest-to-crest distance of approximately 5 meters and 

 were oriented in a north-south direction. Their clarity and uniform shape suggest that 

 they produced by some physical force acting upon the sea-floor sediments. As this dive 

 was made primarily for acoustic measurements, little time was devoted to determining 

 whether or not the current was present. 



Figure 17. Holes, sculpturing, trails, and living nemertean worms suggest a significant amount of biological 

 activity at 270 meters depth west of Capri. The nemertean worm extends itself, left of center, to feed along 

 the surface of the sea floor. Numerous other holes penetrate the sediment. 



20 



