( Benthos ( ( live ( ( ( on ( ( the bottom ) ( -LRB- ( epifauna -RRB- ) ) ) ) or ) ( within ( ( the sediments ) ( -LRB- ( infauna -RRB- ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Benthos)) (VP (VBP live) (PP (PP (IN on) (NP (NP (DT the) (NN bottom)) (PRN (-LRB- -LRB-) (NP (NNP epifauna)) (-RRB- -RRB-)))) (CC or) (PP (IN within) (NP (NP (DT the) (NNS sediments)) (PRN (-LRB- -LRB-) (NP (NNP infauna)) (-RRB- -RRB-)))))) (. .)))
Benthos live on the bottom ( epifauna ) or within the sediments ( infauna ).
(ROOT (S (NP (NP (VBG Living) (NNS things)) (PP (IN on) (NP (DT the) (NN ocean) (NN floor)))) (VP (VBP are) (VP (VBN known) (PP (IN as) (NP (NNS benthos))))) (. .)))
Living things on the ocean floor are known as benthos.