SUMMARY: Lineola, a new bacterial genus, is characterized by large and very long cells of an unusual type and by the formation of motile trichomes of considerable length which may be branched. Two species were isolated in pure culture by the use of capillary pipettes. Even when their nutritional requirements were known it was difficult to purify them by plating. The growths of the two species on agar are different because the trichomes of L. articulata are much softer than those of L. longa. The cells of both species contain a large number of nucleoids and divide by constriction. In L. longa the daughter cells remain firmly connected, whereas in L. articulata the links become pliable, the whole chain-like trichome bending when swimming. Both species are Gram-negative and have numerous flagella. No spores were found. Media with peptone, meat extract, yeast extract, and the like must be supplemented with acetate and with agar or certain other substances, to support multiplication.