SUMMARY: Twenty-five strains currently classified into 14 serological types or species of the genus Vibrio obtained from the NCIB and NCTC have been studied in detail for morphological, cultural and biochemical characters in two independent studies. The results indicate that these strains include members of three distinct taxonomic groups or genera, Vibrio, Pseudomonas and Comamonas. The new generic name Comamonas, type species C. percolons, replaces Lophomonas (Galarneault & Leifson) which is invalid.