A study was made of the slime and faeces of 43 fish, representing 11 marine species taken at Halifax, N.S., St. Andrews, N.B., and Woods Hole, Mass. Eighty species and varieties of bacteria were isolated, 22 from slime only, 14 from faeces only, and 44 from both slime and faeces. These have been identified as far as possible. In some cases, particularly in the genera Achromobacter and Flavobacteria, new groupings are suggested. Members of the genera Achromobacter, Micrococcus, Flavobacterium, Pseudomonas, Bacillus, Eberthella and Proteus were represented, with the first two the most prominent. This study would indicate that the flora of the slime and faeces of marine fish is quite similar.