The Skeleton 61 
two nasals form a narrow rod of bone that extends 
across the anterior nares, and, meeting a projection 
from the premaxillaries, divides the opening into 
right and left halves. In the crocodile the nasals 
project only a very little way into the nares; in 
the caiman (according to Reynolds) they do not 
extend into the nares at all, and in the gavial, whose 
much elongated snout is mainly due to the great 
length of the maxillaries, the nasals do not extend 
more than a third of the distance from the pre- 
frontals to the anterior nares. 
The maxilla (2) is a large bone that forms a large 
part of the upper jaw and that holds most of the 
teeth of that jaw. On the ventral side, as will be 
described later, it articulates with its fellow in the 
middle line, with the premaxilla, with the palatine, 
and with the transpalatine. Dorsally it articulates 
with the premaxilla in front; with the nasal and 
prefrontal on the medial side; and with the 
lachrymal and jugal behind. 
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 premaxille 
on the ventral side is the large anterior palatine 
foramen. 
