From muscle tissues of the marine snail (Turbo cornutus) aminoalkylphosphonyl cerebrosides, which had been shown to be present in visceral parts were isolated. Their structure was determined by degradative methods and by characterization of components by gas chromatography-mass spectrometry. The aminoalkylphosphonyl cerebroside fraction consisted of a major portion of 1-O-[6'-O-(N-methylaminoethylphosphonyl) galactosyl] ceramide and a minor portion of a novel lipid, 1-O-[6'-O-(aminoethylphosphonyl)galactosyl] ceramide. The fatty acids of the fraction were mainly palmitic (53.3%) and 2-hydroxy palmitic acid (14.6%). The long chain bases were mainly dihydroxy C22: 2(36.6%), C18:1 (14.6%) and trihydroxy bases were also found as minor components.