The polysaccharides from an aqueous extract of a Carpopeltis species from the southeastern coast of Madagascar were examined by 13 C NMR spectroscopy. Over 80% of these polysaccharides comprised 3-linked D-galactose units that were non-substituted, 4-sulfated or 4,6-pyruvylated, and these alternated with 4-linked 3,6-anhydro-D-galactose units, some of which may have been 2-sulfated. There were also 4-linked 3,6-anhydro-L-galactose units present, which alternated primarily with 3-linked galactose-2-sulfate units. The natural extract contained 4-linked D-and L-galactose, many, but not all of which, were 6-sulfated and hence anhydrogalactose precursors, and there were minor components containing 2- O -methylanhydrogalactose, 6- O -methylgalactose, xylose, 2- O -methylgalactose, 3/4- O -methylgalactose. This is the first characterization of the galactans from a Carpopeltis species.