A class of almost contact Riemannian manifolds

Recently S. Tanno has classified connected almostcontact Riemannian manifolds whose automorphism groups have themaximum dimension 9. In his classification table the almost contactRiemannian manifolds are divided into three classes: (1) homogeneousnormal contact Riemannian manifolds with constant 0-holomorphic sec-tional curvature if the sectional curvature for 2-planes which contain