The _premaxilla_ (1) forms, with its fellow, the extreme tip of the upper jaw. Each bone forms the anterior and lateral borders of its half of the anterior nares. It articulates medially with its fellow and posteriorly with the nasal and maxilla. Ventrally, as will be noted later, it bears five teeth and articulates with its fellow medially and with the maxilla posteriorly. Between the premaxillæ on the ventral side is the large anterior palatine foramen. The _lachrymal_ (3) is a fairly large bone that forms the anterior border of the orbit. It is bounded laterally by the jugal, anteriorly by the maxilla, and medially by the prefrontals. Its postero-medial border is pierced by a large lachrymal foramen that extends lengthwise through the bone and opens, at its anterior end, into the nasal chamber. The _supraorbital_, missing in the skull figured, is a small bone lying in the eyelid close to the junction of the frontal and prefrontal. Being unattached it is usually absent from prepared skulls. The _jugal_ or _malar_ (5) is an elongated bone that forms a part of the lateral border of the head, on the one hand, and most of the lateral border of the orbit on the other. Anteriorly it articulates with the maxilla; medially with the lachrymal and prefrontal; posteriorly with the quadratojugal, and ventrally with the transpalatine. With the transpalatine it sends, in a dorso-medial direction, a process that meets the process, described above in connection with the postfrontal, to form the postorbital bar. The _quadratojugal_ (12) is a small bone, wedged in between the jugal in front and the quadrate behind. [Illustration: FIG. 20. VENTRAL VIEW OF THE SKULL OF THE ALLIGATOR (_A. Mississippiensis_). 2. maxilla. 5. jugal. 8. quadrate. 9. palatine. 10. pterygoid. 11. transpalatine. 12. quadratojugal. 14. basioccipital. _a_, anterior palatine vacuity; _eu_, opening of the median Eustachian canal; _pn_, posterior nares; _pv_, posterior palatine vacuity.] The _quadrate_ (8) is more irregular and has more complicated articulations than almost any bone in the skull. Its posterior end, which forms the articular surface for the lower jaw, is elongated laterally and slightly concave. Anteriorly the quadrate articulates with the quadratojugal; medially with the basisphenoid and exoccipital; dorsally with the exoccipital, squamosal, postfrontal, and, possibly, with the pro-otic; ventrally with the pterygoid, alisphenoid, and probably with some of the otic bones. Its dorsal side forms most of the floor of the external auditory meatus which will be described later. While the basioccipital may be seen from the dorsal side, it is not really one of the dorsal bones of the skull and will be described later; the same is true of the pterygoids and palatines which may be seen through the empty orbits.