Similarity of trademarks is judged based upon appearance, sound, and meaning, as Sazerac recently reminded us.  Sazerac, the makers of Buffalo Trace bourbon sued  Intercontinental Packaging Company d/b/a Crosby Lakes Spirits Co. over their Bison Ridge brand of Canadian whisky.  While “buffalo” and “bison” are different is appearance and sound, they are one in the same animal, the scientific name of the American Buffalo is bison bison.  It will be interesting to see whether similarity of meaning carries the day.