35. 



do not form cohesive groupings. Interestingly, the distri- 

 butions of Cevianthus horealis and Boloaera tuediae are not 

 correlated in Baltimore Canyon, while they are correlated 

 in Lydonia Canyon. It is quite possible that the appropriate 

 environmental factors required by B. tuediae are not found in 

 Baltimore Canyon in the depth range inhabited by C. horealis . 

 Another possibility is that B. tuediae which requires hard 

 substrate for attachment, is excluded from shallow water in 

 Baltimore Canyon by the presence of the large white anemone. 

 This difference, however, does indicate that B .tuediae is not 

 restricted to a discrete depth range. 



The ten end-members of the fauna of Lydonia Canyon are 

 identified and plotted in Figure 17. Again, the pattern for 

 the shallow-water assemblage is one of gradual replacement of 

 species across bathymetric contours. Munida valida (6) 

 dominates the fauna above 200 meters, while three anemones, 

 Cerianthus horealis and Bolocera tuediae (7) and a small encrust- 

 ing anemone (5) gain importance in the slightly deeper fauna. 

 On the east flank and wall of Lydonia Canyon this pattern is 

 quite obvious with the anemone (5) , which is attached to the 

 glacial erratics found in this area, gradually being replaced 

 by Eyalinoeoia artifex (2) at increasing depths. The fauna of 

 the west flank and wall of the canyon is consistently dominated 

 by Geryon quinquedene (4) above 500 meters, which is replaced 

 by Synaphohranahus kaupi (3) and shrimp (1) at greater depths. 



