High-field 1H-n.m.r.-spectroscopic studies supported by chemical carbohydrate analyses show that skeletal keratan sulphates (KS-II) of bovine origin may be sub-classified into two groups. Keratan sulphate chains from articular and intervertebral-disc cartilage (KS-II-A) contain two structural features, namely alpha(1----3)-fucose and alpha(2----6)-linked N-acetyl-neuraminic acid residues, that are absent from keratan sulphates from tracheal or nasal-septum cartilage (KS-II-B).