Diatom taxonomy is presently confined to characters of the silicous cell wall of these single celled algae. The raphe has been accepted as an important and conservative taxonomic character in pennate diatoms. A simple raphe consists of a slit in the diatom cell wall that opens directly into the inside of the valve. In a canal raphe system, there are silicous structures (fibulae) that create a duct into which the raphe opens inside the valve. Entomoneis ornata (J.W. Bail.) Reim. has previously been classified with the order Naviculales, which has the characteristic of a simple raphe system. Entomoneis ornata was examined and was determined to have a canal raphe system warranting the removal of this species and possibly the entire genus from the order Naviculales.