| OCR Text |
Show 1867.] PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. 4 37 or less ossified. The basipterygoid processes are represented by oval facets, sessile upon the rostrum, and placed so far forward that the surfaces which articulate with them are situated close to the anterior extremities of the pterygoid bones. In this respect, in the rudimentary condition of the inner lamina of the palatine bone, and in the circumstance that the angle of the mandible is strongly produced and upcurved, these resemble the Gallinaceous birds. They differ from the latter not merely by their " desmognathism" but by the absence of the rounding off of the postero-external angle of the palatine, which is so marked in the Fowls, and by the great proportional length of the region of the skull, which corresponds with the attachment of the lachrymal bone (Fr to Na, nearly, in fig. 18). In Lbis, Platalea, and Phoenicopterus the maxillo-palatines not only unite across the vomero-palatine fissures, but, becoming enlarged and spongy, fill the base of the beak. The basipterygoids, rudimentary in Phoenicopterus, are absent in Platalea and Ibis. The angle of the mandible of Phoenicopterus has the same prolongation Fig. 19. Under view of the skull of Ardea cinerea. The letters as before. |
