From pink solar salt an obligate halophilic bacterium was isolated and shown to be the cause of the pink discolaration. Method of isolation, cultural characteristics and nature of pigment are detailed. The bacterium proved to be closely related to previously described halophilic bacteria, andVolcani's suggestion that all such bacteria should form a genusHalobacterium seems acceptable. Further work however is indicated, especially as the present bacterium showed such unusual morphological features. Examined in the live state, by means of phase contrast microscopy, or preferably sunlight dark field methods, this bacterium usually did not present itself as a cylinder, but appeared flat as a ribbon, and in addition this ribbon often showed one or more twists (up to 180c) per individual bacterium. This resulted in a spiral appearance of the bacterium, and its motility seemed to make use of this spiral configuration. Confirmation of this curious kind of morphology and motility was sought and found through the study of spiral glass models, and by means of cine-micrography1). Flagella were not found. It is suggested, and there are some indications, that other bacteria of this group, and perhaps of other groups, might on similar examination in the live state, be found to show similar shapes.