OCR Text |
Show 434 PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. [Apr. 11, In the Cracidee the characteristic basipterygoid processes, the produced and recurved angle of the mandible, and the form of the palatines remain as in the last mentioned genera. But the maxillo-palatines are large and scroll-like, stretching inwards, and in some species (e. g. Crax globicera) even becoming united across the middle line with one another and with a small ossification of the septum narium. All Columbidce (except Didus) have basipterygoid processes, and are completely Schizognathous. The maxillo-palatines are larger than in the ordinary Gallinaceous birds, and are elongated from before backwards, and spong)r in texture, not scroll-like. The postero-external angles of the palatine bones are rounded off; but, in most of the Columbidce, their inner laminae are more prominent than the outer, instead of being obsolete as in the Gallinaceous birds. The basipterygoid processes are prominent and rather resemble those of the Plovers than those of the last-named group. Finally, the angle of the mandible is neither produced nor recurved, but is more or less abruptly truncated. The vomer is very slender. Under view of the skull of Columba palumbus. The letters as before. Didus has no basipterygoid processes ; but the articular end of its mandible resembles that of other Columbidce. Didunculus more nearly resembles the ordinary Columbidce in possessing prominent basipterygoid processes ; but the palatine bones are thick, their internal laminae being altogether obsolete. The distal articular facet of the quadrate bone is elongated antero-posteriorly, and nearly resembles the same part in a Parrot. The axis of the fossa of the mandible which receives this facet nearly coincides with that of the ramus of the mandible; while in the other Columbidce |