The _palatine_ (fig. 60, 20) is a slender irregular bone flattened dorso-ventrally at its anterior end where it articulates with the beak, and laterally behind. It gives off at its posterior end a process, which is sometimes united with the vomer, sometimes projects forwards, and meets its fellow dorsal to the vomer. In the large space between it and the vomer is the opening of the =posterior nares=.
The _premaxillae_ (figs. 59 and 60, 2) are very large, and form nearly a third of the big shovel-shaped beak. They constitute the inner, and part of the front boundary of the anterior nares, and send back a pair of _nasal processes_ which partially separate the nasals from one another.
The =outer arcade= forms the slender =suborbital bar=, and consists mainly of two rod-like bones, which in the adult are completely fused together. The posterior of these is the _quadratojugal_ (figs. 59 and 60, 11) which articulates with the quadrate, the anterior is the small and slender _jugal_ or _malar_ (figs. 59 and 60, 10). The extreme anterior part of the bar is formed by the _maxillae_. The main part of the maxillae however lies anterior to the suborbital bar, and extends forwards along the side of the premaxillae forming all the lateral part of the beak (figs. 59 and 60, 1); it also sends inwards a plate, the =maxillo-palatine= (fig. 60, A, 29), which completely fuses with its fellow in the middle line, and forms the posterior boundary of the anterior palatine foramen. The term =desmognathous= describes the condition of the skull in which the maxillo-palatines fuse with one another in the middle line in this way.
The =quadrate= (fig. 60, 12), which unites the two arcades behind, is a stout irregular four-cornered bone forming the =suspensorium=. It articulates by its dorso-posterior corner with the squamosal, and by its antero-internal corner with the pterygoid. The middle of its ventral surface forms a hemispherical knob with which the mandible articulates, while its dorso-anterior border is drawn out into a long point which extends towards the interorbital septum.
The =mandible= or lower jaw consists of two =rami= which are flattened and fused together in the middle line in front, while behind they diverge from one another and articulate with the quadrates.