Dysganus bicarinatus, sp.nov.

This dinosaurian is represented in the collections by some of the teeth of three individuals. Two of the teeth represent immature stages , while the others are worn by continued use. They all present characters not found in the D. encaustus, from which they differ in a direction the opposite of that which characterizes the D. haydenianus.

The crowns present a nearly flat face without incurved lateral angles, nor prominent median keel. The basis is widle, projects in a rim beyond the face, and is invested with rough cementum. The face is peculiar in beinig divided into three planes by two low angular ridges, and its surface is smooth. The dentinal column is triangular, and there are two posterior columns separated by a fissure, in mature teetlh.

The absence of the lateral incurved angle, and the presence of the two median ones distinguish this species from the D. encaustus.