Answer: ectoderms

AnswerCrossword Clue
ECTODERMSEmbryological layers
ectodermsthe outer cellular membrane of a diploblastic animal (as a jellyfish)
ectodermstissue (as neural tissue) derived from this germ layer
ectodermsECTODERM, the external layer of an embryo, also EPIBLAST, EXODERM