part of part of overlaps overlaps pharyngeal arch 3 3rd arch pharyngeal cleft pharyngeal pouch 3 pharyngeal membrane pharyngeal membrane of 3rd arch 3rd pharyngeal membrane UBERON:0009216 EMAPA:16583 VHOG:0000876 In all vertebrates, the endodermal epithelium lining each pouch contacts the surface ectoderm of the clefts to form a series of bilayered branchial membranes, that break down in fish to form the gill openings.[well established][VHOG] A pharyngeal membrane that separates the third pharyngeal cleft from the third pharyngeal pouch.