1. Six carotenoid pigments were produced by and isolated from the green alga Dictyococcus cinnabarinus grown in submerged culture in the presence of glucose. 2. The first, second and fourth pigments were identified respectively as beta-carotene, echinenone and canthaxanthin; the physicochemical properties of the other three are described and their similarity to other oxo-carotenoids is shown. 3. Culture techniques, isolation and identification procedures are described.
