The Skeleton 63 
quadrate articulates with the quadratojugal; me- 
dially with the basisphenoid and exoccipital; dor- 
sally 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. 
The Ventral Aspect (Fig. 20). The larger part 
of this side of the skull is made up of four pairs of 
bones: the premaxille, the maxille, the palatines, 
and the pterygoids, lying, from anterior to posterior, 
in the order named. 
The premaxilla (1), as described in the dorsal 
view of the skull, is a triangular bone which, with 
its fellow, forms the anterior end of the snout. 
Each premaxilla bears five teeth, not only in the 
alligator but in the crocodile, the caiman, and in the 
gavial. Of these teeth the fourth from the front 
is the largest; the first two are small, and the 
third and fifth are of intermediate size. This 
arrangement as to size is also true, apparently, in 
the other groups of Crocodilia. The ventral surface 
of the premaxilla, which is more or less flat and 
horizontal, is pierced by a number of small fora- 
mina, in a row parallel to the curved outer margin 
