scala media morphology trait spiral ligament morphology trait Any measurable or observable characteristic related to the shape, structure, color or pattern of the thickened periosteal lining of the bony cochlea that forms the outer wall of the cochlear duct to which the basal lamina attaches. Trait.ontology VT:0004288 crista spiralis morphology trait ligamentum spirale cochleae morphology trait ligamentum spirale ductus cochlearis morphology trait spiral crest morphology trait spiral ligament of cochlea morphology trait spiral ligament of cochlear duct morphology trait