THE SKULL IN THE CHAMELEONS. 81 
with a rounded lower end and a sharp thin upper part—the nasal process (x. pr). Only 
the broad end is seen in the lower view; for the maxillaries (mz) close under it, as they 
close under the paired rudiments in the human embryo! This wedge is thickened again, 
above (fig. 3), where it binds together the two prefrontals; it then runs sharp and thin 
between the nasals. The maxillaries (ma) are large bones, high in front, and gently 
lessened backwards into a sharp jugal process. In front they have a deep round notch, 
in which the outer nostril and its enclosing cartilages (¢.n, al.n) lie. In front each bone 
is not far from its fellow, and is ornate; behind the nostril the bone rises as a strong 
rounded process, which props up the prefrontal. Descending thence in a crescentic 
manner, it leaves a space for the small oblong lacrymal (fig. 1, 1), inside which is seen 
the large triangular lacrymal canal (/.¢), bounded on its inside by the anteorbital 
plate of the prefrontal. 
Only the maxillary (above) bears teeth; and these are confluent with the jaw. 
From the lacrymal the jugal (7) runs back, no larger than it at first; but bending 
up behind at more than a right angle, it becomes a broad antl thick bar, finishing the 
orbit, propping up the fore fork of the squamosal, and is itself clamped in front by the 
styloid lower crus of the postorbital. 
The lower surface of the skull (fig. 2) shows the maxillary as having a wide palatine 
plate up to its junction with the palatine bone (pa); thence it becomes less than 
half its anterior width. Behind the junction of the maxillaries in front, in the semi- 
oval space formed by their divergence, we see the single vomer (uv); its length is one 
half greater than its breadth ; its sides are concave ; and so is its inferior surface: it 
projects into the notch between the maxillaries; and the palatines articulate with 
its posterior margin, which is a rounded notch. It isa thick but not very high bone 
(Plate XVIII. figs. 2-5). 
_ The ascending processes of the palatine bones (fig. 2, pa) are united together by 
suture for a greater length than that of the vomer; together these upper arched 
spurs are not equal to the lower flat region of these bones. 
The lower part of each palatine grows outwards and forwards, and articulates 
obliquely with the palatine plate of the maxillary; behind, the inner margin of each 
bone, at the lower plane, approaches the mid line; and thus a grooved space is formed, 
into which both the internal nostrils (choanz, 7.1) open. These passages are large, 
oval, with their long axis parallel to the axis of the skull, and their inner boundary 
the notched tract between the lower and upper part of the palatines. In front of and 
outside each inner nostril there is a membranous space, bounded on its inside by the 
vomer, and on its outside by the palatine process of the maxillary. Above this space, 
and above the vomer, there is in most Lizards, as in the Serpents, a thin curled laminar 
bone—the “septo-maxillary ;” it does not exist in the Chameleon. 
Where the broad lower part of each palatine articulates with the pterygoid (py), 
