| OCR Text |
Show 440 PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. [Apr. 11, The same general arrangement is observable in the Cormorants and the Pelicans; but the inner edges of the palatine bones unite for a much greater distance behind the posterior nasal aperture, and a median ridge is sent down from the line of junction of the palatines. These birds thus present the most extreme modification of the palatine apparatus which is to be observed in the whole class. In the Pelecanidee the inferior edge of the ossified interorbital septum rises rapidly forward so as to leave a space at the base of the skull, which is filled by a triangular crest formed by the union of the greatly developed ascending processes of the palatines (fig. 20). In the Cormorants, on the other hand, the inferior edge of the septum is horizontal, and the crest in question is not developed (fig. 21). In all the Raptorial birds the nasal septum is ossified for a greater or less extent; and the vertical plate thus formed joins below, by Fig. 22. of the skull of Cathartes aura. From a specimen in the Museum of the Royal College of Surgeons. The letters as before. + The basipterygoid processes. |
