SUMMARYTheConchocelisphases ofPorphyra perforataf. patens, P. cuneiformisandP. nereocystiswere cultured from spores in a sterile artificial medium at 12 C and with 25 ft‐c illumination for 10 hr daily. The cultures showed differences in duration of the vegetative phase, sporulation, liberation of spores, and the return to the leafy phase. Morphological differences were also noticed. Since the 3 species were grown under identical conditions, it is inferred that these characteristics are probably different for the 3 species studie