What catcher has CAUGHT the most no-hitters?

I know Nolan Ryan PITCHED seven no-no’s – the most of all time. BUt who CAUGHT the most?

See for yourself:

http://www.geocities.com/Colosseum/Bleachers/1203/catchno.htm

Fifteen different catchers have caught three no-hitters, the latest being Charles Johnson (Al Leiter, 1996; Kevin Brown, 1997; A.J. Burnett, 2001). However, the record is held by Ray Schalk, who caught four in his Hall of Fame career.

Catching Three No-Hitters