 The "extraordinary" ray, or "e"-ray, experiences a lower refractive index ("n"e = 1.486) in the calcite and is not totally reflected at the interface because it strikes the interface at a sub-critical angle.The "e"-ray merely undergoes a slight refraction, or bending, as it passes through the interface into the lower half of the prism.It finally leaves the prism as a ray of plane-polarized light, undergoing another refraction, as it exits the far right side of the prism.