are presented. There are three types: (1) straddling tricuspid orifice entering both primitive ventricles with the mitral valve entering the left ventricle (nine cases), (2) displaced tricuspid orifice into the primitive left ventricle, with no A-V orifice in the primitive right ventricle (three cases), and (3) displaced tricuspid orifice with straddling mitral valve, in which the mitral valve ...