Features of ordinary and extraordinary rays travelling through an optically anisotropic prism with total internal reflection on one of the faces are considered in the paper. Special attention is paid to the process of extraordinary ray reflection from the face of total internal reflection. Ray propagation was investigated for prisms made of four optically uniaxial crystals (TeO<sub>2</sub>, CaCO<sub>3</sub>, Hg<sub>2</sub>Cl<sub>2</sub>, Hg<sub>2</sub>J<sub>2</sub>) having different optical signs and values of birefringence. Possible ways of ray propagation through a prism at different angles of incidence on the prism and different directions of ray propagation within the prism were calculated. The examined features allow channels in fiber-optical communication systems to be split by optical means.