of the tip of the beak. It will be seen that the conformation of the upper surface of the beak is quite different from that of _bidens_ or any other species. The maxillary foramina are large and directed forward, and have a distinct broad channel in front of them. In the Oregon skull the right foramen is single, but the left divided into two. The premaxillary foramina are a little behind the maxillary foramina. The distance between the maxillary foramina is less than that from the median line to the anteorbital notch. In _bidens_ it is much greater. _Lateral aspect_ (Pl. 9, figs. 1, 2).—A most noteworthy feature of the skull when viewed from the side is the great length between the orbit and the maxillary notch, which far exceeds that found in _bidens_ and other species, being equal to the length of the orbit itself. The latter is about as long as the temporal fossa, which is somewhat flattened above, as in _europæus_. The outline of the supraoccipital is straight and nearly vertical. The zygomatic is more massive even than _europæus_ and is especially thick below. The inferior outline of the beak is convex proximally as in _europæus_ and _layardi_. There is no basirostral groove, the edges of the maxillæ being very thick in front of the maxillary notch. Over the orbit the maxillæ are thick and beveled, but not raised as in _bowdoini_. _Ventral aspect_ (Pl. 6, figs. 1, 2).—The beak is convex in the proximal half, much as in _europæus_, but farther forward is concave, except in the median line, where there is a narrow ridge formed proximally by the vomer, which in the type skull appears as a narrow lozenge 60 mm. long. In the adult Oregon skull it is anchylosed with the premaxillæ. The maxillæ extend to within 107 mm. of the end of the beak. The under surface of the beak is much more like that of _europæus_ than of _bidens_. A narrow strip of the palatines extends around the base of the pterygoids in front, but the two strips do not meet in the median line. In the type-skull they do not extend inside the pterygoids. The expanded anterior end of the malar is very long and also forms the bottom of the maxillary notch, which is the case in _europæus_ but not in _bidens_. The inferior borders of the pterygoids are convex anteriorly, as in _europæus_, and are continued laterally, so that the sinus is deep as in that species. The lachrymal is very long, the free margin having a length of 55 mm. The posterior margin of the zygomatic process is concave, rather than convex as in _bidens_.