( ( ( ( Included ( in ( this subclass ) ) ) ( are amniotic ) ) ( ( ( ( ( sac , ) ( corpus luteum ) ) , ) and ) ( ( ( whole embryo ) or ) fetus ) ) ) . )
(ROOT (SINV (VP (VBN Included) (PP (IN in) (NP (DT this) (NNS subclass)))) (VP (VBP are) (ADJP (JJ amniotic))) (NP (NP (NN sac)) (, ,) (NP (NN corpus) (NN luteum)) (, ,) (CC and) (NP (NP (JJ whole) (NN embryo)) (CC or) (NP (NN fetus)))) (. .)))
Included in this subclass are amniotic sac, corpus luteum,  and whole embryo or fetus.
(ROOT (S (NP (NP (DT The) (JJ amniotic) (NN sac)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBD was) (VP (VBG sitting) (PP (IN on) (NP (NP (NN top)) (PP (IN of) (NP (DT the) (JJ flat) (NN embryo))))))))) (, ,)) (VP (VBZ envelops) (NP (DT the) (NN embryo)) (SBAR (IN as) (S (NP (PRP it)) (VP (VBZ folds))))) (. .)))