Cope.]

[Nov. 15, region. The palatopterygoid arch has the relations prevalent in the Stegocephalia, but what is novel so far, its anterior and chiefly palatine portion carries a single series of teeth on the external and anterior border, which is concentric with the premaxillo-maxillary series, as in Cryptobranchus. Posterior to this is a pair of straight series of teeth, probably on the vomers, which form an anteriorly directed right-angle at the middle line. They do not extend so far posteriorly as do the maxillary teeth, and the latter do not extend so far posteriorly as the pterygopalatines, which terminate at a straight line drawn through the posterior borders of the orbits. The posterior nostrils are situated between the two series of palatal teeth. The external nostrils open forwards and outwards. Maxillary and premaxillary teeth twenty-three on each side. Palatines, twenty-four; vomerines, ten.

The composition of the huge horns is thus the result of the fusion of the three posterolateral roof-elements into one, thus obliterating the notch which separates the tabular from the quadratojugal bones in most other Stegocephalia.

DIPLOCAULUS LIMBATUS, sp. nov.

This species is represented by a number of fragmentary skeletons and skulls. One of these I describe as the type since it displays more of the characters than any other, but it is nevertheless damaged anterior to the orbits, so that the form of the muzzle is not accurately determinable.

The character of the species is seen in the horns. These are much less produced relatively to other regions than in the D. magnicornis, and the postquadrate (quadratojugal) element is more distinct, and terminates in a separate apex below the principal horn. This tract, which is fused with the principal bone in the D. magnicornis, is separated from it by a groove in the D limbatus, and the large fossa which it encloses with the inferior side of the principal horn looks inwards at an angle of 450, while it looks downwards in the D. magnicornis. The terminal angle of the quadratojugal (postquadrate) body forms a prominent compressed offset, rather than a free apex. In one specimen of large size it is infero-lateral; in the type, entirely inferior. The principal horn is shorter and narrower than in the D. magnicornis, and less divaricate.

As the mandibular rami are in place and their extremities are entire, the length of the muzzle can be inferred. It is relatively longer and less broadly rounded than in the D. magnicornis. The surfaces of the skull are sculptured in honeycomb pattern, as in the type species.