40. 



to Oceanographer Canyon, where shrimp (1) , rattails (2) , 

 SynaphobranahuB kauyi (6) and sponges (4) again predominated, 

 with occasional occurrences of a burrowing cerianthid anemone 

 (9). 



The main differences in the fauna between Baltimore 

 Canyon and the two northern canyons are in taxa that prefer or 

 require hard substrates. Both Oceanographer and Lydonia 

 Canyons support sizable populations of these organisms, in 

 addition to the fauna usually found in soft substrate areas. 

 One other noticable difference among the faunal components 

 of the three canyons is that the quill worm Eyalinoecia artifex 

 does not dominate any of the areas in Oceanographer Canyon. 

 This is the result of no shallow-water coverage in that canyon 

 and also reflects the patchy distribution of this species. 

 However, many individuals of U. artifex were found in the axis 

 of this canyon during the historical survey (Appendix A) . 



Depth zonation 



The dominant epifauna observed in the three canyons can 

 generally be divided into the major depth zone groupings delin- 

 eated by Haedrich, Rowe and Polloni's (1975) study of epifaunal 

 zonation on the slope south of New England. The common taxa 

 or species were ranked by their relative abundance, rather 

 than numerically, in the depth zone in which they comprised 

 the greatest proportion of the fauna. This method alleviates 



