The cement (c) covers the root of the tooth that projects into the alveolus of the jawbone; it is much more strongly developed than in the lizards and contains a very large number of bone corpuscles which are distinguished from the bone corpuscles proper by their greater circumference. The fairly large pulp cavity (p) has, like the tooth itself, a conical form. Parallel to the teeth is a row of small foramina, a continuation of those noted in the premaxilla; some or all of these foramina open into a longitudinal sinus along the alveolar border of the maxilla; this sinus opens posteriorly by one or more large apertures into the posterior palatine vacuity. The _palatines_ (9) form a broad bar of bone from the pterygoids behind to the maxillæ in front. They are united with each other by a straight median suture and form a considerable part of the floor as well as a part of the side walls and roof of the nasal passage. They form most of the median boundaries of the posterior palatine vacuities (pv). Dorsally they articulate with the pterygoids, prefrontals, and vomers. The _pterygoids_ (10) are the very irregular bones that project ventrad and caudad from beneath the orbits. Their suture is continuous, caudad, with that between the palatines and at the posterior end of this suture is the posterior opening of the nasal chamber, the posterior nares (pn). This opening is divided by a vertical, longitudinal, bony septum, and the part of the chamber into which it immediately opens, which lies in the pterygoids, is divided by a number of transverse, vertical septa. Posterior and dorsal to the posterior nares the pterygoids are fused. Anteriorly the pterygoids articulate with the palatines; dorsally with the quadrates, basisphenoid, alisphenoids, and prefrontals, and dorso-laterally with the transpalatines. The lateral vertical border of the pterygoid is roughened and is, according to Reynolds, covered, during life, with a pad of cartilage against which the medial side of the mandible plays. The _transpalatine_ (11) is a T-shaped bone articulating ventrally with the pterygoid and dorsally with the maxilla, the jugal, and the postfrontal. [Illustration: FIG. 20A. LONGITUDINAL SECTION OF THE JAW AND TOOTH OF A CROCODILE. (After Bronn.) _c_, cement; _d_, dentine; _e_, enamel; _p_, pulp, of functional tooth; _c′_, cement; _d′_, dentine; _e′_, enamel, of rudimentary tooth; _e″_, epidermis; _k_, bone of jaw.] The _basioccipital_ (14) is seen projecting caudad as the single occipital condyle; it will be described in connection with the posterior aspect of the skull. The _jugal_ (5), _quadratojugal_ (12), and _quadrate_ (8) may all be seen from this view. The first two have been sufficiently described in connection with the dorsal aspect; the last will be further described in connection with the lateral aspect. Just caudad to the posterior nares is a small opening, the unpaired Eustachian canal (eu).