(4) The most abundant teeth are much smaller, with no crenulations, and the posterior ridge sharp and not grooved. The wear is in front of the apex, and on one side, sometimes on both sides, as in. figure 6, Plate III.

*Proc. Acad. Nat. Sci. Philadelphia, p. 198, 1868.

This tooth may be taken as the type of a new species, Aublysodon cristatus .