What came before the Type 97 machine gun?

Don't know what the odds are that anyone here can answer that. Japanese Type names are taken from the year of acceptance, and it rolls over at 100. If "Type 0" is 1940, then "Type 97" would be 1937. What did the Japanese Navy use as a fixed cowling gun before 1937 then? I can believe that the "Type 96" (A5M) fighter used Type 97 guns, but what about older Japanese fighters? I assume it was another Vickers type, but what was the Type number? And was it a direct copy? And of course, that makes me wonder about the Army and what they used before the Type 89 (another Vickers type).
I always find myself wondering about the most unimportant stuff.