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Show 1895.] LORIUS FLAVOPALLIATUS AND PSITTACUS ERITHACUS. 385 coincides with the uppermost (and most concave) part of the postaxial margin of the external auditory meatus. Below this, again, is the nearly straight lower part of this margin, which inclines slightly inwards as it descends, and is bounded inferiorly by the sudden out-jutting of the zygomatic process of the quadrate for the zygoma together with the posterior end of the latter. Below this is the lateral outline of the quadrate, which is nearly straight and vertical to the rounded inferior end of that bone. In L. flavopalliatus the median concavity of the dorsal margin is less marked ; the lateral margin is generally similar to that of the other species save for the much less, relative as well as absolute, extent of the part formed by the quadrate below its zygomatic process, and that the sphenotic process (sph) is seen projecting outwards beyond the posterior margin of the external auditory meatus. The suprameatal process (sm) projects sharply outwards. Ym. 11 sm Postaxial aspect of skull of Lorius flavopalliatus. Ir. Lambdoidal ridge. oc. Occipital foramen. par. Paroccipital process. po. Postorbital process. pt. Palatine. q. Quadrate. sm. Suprameatal process. sph. Sphenoidal process. z. Zygoma. The inferior margin of the cranium, thus seen, is, in P. erithacus, formed externally by the two zygomatic processes of the quadrate. Next within comes the inferior border of each quadrate, and then that surrounding the deep and sudden notch which divides each quadrate from the paroccipital process, which does not descend as much as does the quadrate. The median part of the inferior margin (apart from the palatines) presents a low arch medianly interrupted by the projection downwards of its keystone-the basi-occipital with its condyle. This margin in L. flavopalliatus is similar save that the paroccipital processes descend almost as m u c h as do the quadrates. On this view the palatines are seen descending and diverging at PROC. ZOOL. Soc-1895, N o . X X V . 25 |