On the osteology of Balaeniceps rex (Gould) / by W. Kitchen Parker.

  • Parker, William Kitchen, 1823-1890.
Date:
1860
Catalogue details

Licence: Public Domain Mark

Credit: On the osteology of Balaeniceps rex (Gould) / by W. Kitchen Parker. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    42/96 (page 308)
    of each ramus. The inner margin of each half is then notched once or twice, and then becomes again crescentic in outline, just behind the articulation with the palatine turbinals. The vertical middle portion of the palatines, at their coalescence, is full of large vacuities, the mesial line becoming more consistent where these bones coalesce with the triangular knife-like vomer. This bone (the vomer) is one-third of an inch long, the same at its base, convex in outline above, and concave below; the latter part having a round margin, whilst the former is sharp. The large coalesced palatines of this bird—each half of which, from its broad anterior origin, may be said to be piano- convexo-concave (the concavity on each side the mesial keel, and for an equal distance anterior to it, being very large)—form a very noble structure. No other bird seen by the writer has similar palatines. Those of the Boat-bill are distinct, broad, and flattened out, like the same hones in the Podargus, although in the latter bird they are coalesced. The vomer also is larger in the Boat-bill, and unites with the palatines on each side. In the large Adjutant the palatines are considerably less than in the Baleeniceps, and are partly coalesced, but retain the type of structure common to the Storks and Herons, viz. a strong external and a sub-mesial keel to each bone, whilst the mesial line itself is concave below. In the Heron the palatines are very long and delicate, and are totally distinct from each other, except that at their middle they are tied together, as it were, by each of them sending an internal process forwards to be anchylosed to the vomer, which is here rather more developed. In other fish-eating birds, where the motions of the upper jaw on the cranium are strong, we find that the coalesced palatines have the same essential structure as in the Balseniceps. In the Pelican, for nearly an inch, the palatines are flat, elastic, and quite separate ; they then unite together, become stronger, have at first a thick, and then a thin margin, as in their hinder third they contract in width to articulate with the ptery- goids. Between these thick margins a very strong keel is developed both above and below at the mesial line; and these keels run backwards, the upper to the articular surface on the basi-sphenoid, and the lower to the part where the pterygoids are attached. Behind the upper keel the palatines are scooped neatly to receive the basi-sphenoid, and behind the lower they are slightly notched. The end of each moiety of the bone, besides contributing to form the sphenoid groove, has two articular facets for each ptery- goid, and there is a notch between the upper and lower facets. The palatines are nearly three inches and a half long in the Pelican. In the Cormorant and Gannet the struc- ture is essentially the same; but they are long and parallel in outline, like those of the Heron. In these smaller Totipalmatae the whole concave line of coalescence glides along the base of the orbital septum, just as in Balseniceps. In this great Heron {Balce- niceps) we have a modification of the palatines not entirely unlike what is found in the Pelican, for the sake of strength and mobility in the upper jaw. In the Hornbill, as well as in the great Goatsucker, the palatines are coalesced ; but this is an excep- tional condition in birds. These bones are relatively small in Struthious birds, and they coalesce both with the maxillaries and the pterygoids in the Apteryx. In the Gallinse