1977 Volume 43 Issue 3 Pages 277-288
A marine catenate dinoflagellate having been tentatively applied by the present authors for detectiong carcinogens has been regarded to be Polykrikos schwartzi BÜTSCHLI. However, this species does not belong to the genus Polykrikos for reasons that it is devoid of both syncytium cell structure and nematocysts, but possesses both chloroplasts and phagocytes. This dinoflagellate isnow concluded to belong to the genus Gyrodinium from the theca having both blisters and cortical vesicles, plastids very similar to those of Gyrodinium cohnii and the girdle displacement of 0.23 clearly exceeding the upper limit of that of Gyrodinium.