Ectental

a. [ Gr. 'ekto`s outside + &unr_; inside. ] (Biol.) Relating to, or connected with, the two primitive germ layers, the ectoderm and ectoderm; as, the “ectental line” or line of juncture of the two layers in the segmentation of the ovum. C. S. Minot. [ 1913 Webster ]