( ( The tunicates ) ( ( possess ( ( ( an ( ( open circulatory ) system ) ) ; ) ( one ( that ( ( is largely ) ( without vessels ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS tunicates)) (VP (VBP possess) (NP (NP (DT an) (ADJP (JJ open) (JJ circulatory)) (NN system)) (: ;) (NP (NP (CD one)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (ADVP (RB largely)) (PP (IN without) (NP (NNS vessels))))))))) (. .)))
The tunicates possess an open circulatory system; one that                      is largely without vessels.
(ROOT (S (NP (NNS Echinoderms)) (VP (VBP possess) (NP (DT a) (JJ water-based) (NN circulatory) (NN system))) (. .)))