Abstract
SUMMARY Sixty-one polarly flagellate bacteria, initially identified as such by the type of motility they displayed, were isolated from surface waters and classified on the basis of cultural and biochemical tests into three genera : Aeromorcas, Pseudomonas, Comamonas. Sixteen similarly flagellated cultures from other sources were also found to be members of these genera. Some bacteria with a single polar flagellum and giving reactions of the Alcaligenes type were isolated. It is suggested that the definition of the genus Cornamonas (Davis & Park) be extended to include such forms. The possibility of confusing Aeromonas with Vibrio and with some enterobacteria is discussed.