70. 



canyon exhibits a more complex pattern of substrate distri- 

 bution and has a greater amount of exposed hard substrate 

 when compared with Baltimore Canyon. Lydonia Canyon is small 

 and has a narrow axis with steep walls. In general this 

 canyon appears to be an area of active erosion. Fine-grained 

 sediment predominates on the walls and along the thalweg. 

 Rock outcrops are mainly restricted to the axis with occasional 

 exposures on the walls. Glacial erratics are abundant on the 

 east flank of this canyon and are present in reduced numbers 

 on the west flank. The variety of substrates found in 

 Lydonia Canyon provide a heterogeneous environment capable 

 of supporting large populations of corals and other attached 

 fauna. As a result the fauna below 400 meters frequently 

 differs from that commonly found on the slope. 



(1) Faunal density is uniformly high between 100 and 

 400 meters and is attributable to high concentra- 

 tions of anemones and Eyalinoeoia avtifex. Below 

 400 meters faunal density is uniformly low. 



(2) The major faunal constituents differ from those 

 commonly found in slope habitats. The shallow- 

 water assemblage (100-400 m) is variable and is 

 dominated by Munida valida^ Cer-ianthus borealis ^ 

 Boloaera tuediaBf a small unidentified encrusting 

 anemone and Eyalinoeaia avtifex. Between 400 and 



