OF THE SKULL IN THE CHAMELEONS. 89 



Here the palatines (^a)are cut through both in their upper and lower regions, and the 

 space between the right and left lower laminae is the postnasal channel (i. n). The 

 maxillary (ma:) is lowering down towards the lacrymal bone, and is strongly buttressed 

 by the palatines. 



Section 8. — A little further back (fig. 8) the frontal (f) is twice as wide, and has 

 acquired a tubercular ridge ; its sides turn up and carry the prefrontals (p-f) on 

 them ; it is still slightly carinate below ; the prefrontals are now one third less. 

 The nasal channel (i. n) is now at its most contracted part, and the palatines {pa) 

 at their steepest and widest middle part. The maxillaries {mx) are of the same 

 shape as in the last section. 



Section 9. — The prefrontals have now become still narrower, and the frontal broader 

 (fig. ^,pf,f)\ the latter has lost its lower keel; and the crest above is a mass of 

 tubercles. The palatines {pa) are separated both from the orbital septum (presphenoid, 

 p.s) and from the maxillaries {ms). 



Section 10. — In this section the jugal and jugal processes of the maxillary are not 

 retained, but the roof-bones are shown in situ. This slice is through the common optic 

 passage (fig. 10, ii) and through the hinder part of the frontal {f), where the tubercles 

 crowd between the fenestra and the coronoid suture (see Plate XVI. fig. 3). The 

 thick-crested frontal (/) is very solid at this part ; and at its edges it carries a new 

 pair of bones, viz. the postorbitals {pt. o). As in the last, the valley is shallower and the 

 skull-roof wider. Here the pterygoids {pg) are in section, close in front of the trans- 

 palatines (see Plate XVI. fig. 2, t.pa). 



Section 11. — This is behind the orbits and through the alisphenoid and basisphenoid 

 {^^.11, al.s, I. s); and here the second single roof-bone, the "interparietal" (/.^), is 

 cut through, close behind the coronoid suture. Here we see by this and the last sec- 

 tions that the cranial cavity is much foreshortened the last contained the fore end of 

 that space ; and this part of the cavity is covered by a production of the parietals. This 

 middle bone is very solid ; its sides are now shelving ; and it lies directly on the dura 

 mater. The postorbitals {pt.o) also are shelving, are crested at their outer edge, and 

 then run downwards as a thick facial plate. 



Section 12. — In this section (fig. 12) the roof-bone {i.p) does not rest on the dura mater, 

 but is separated from it by a considerable space ; its crest is higher ; and its sides are 

 thin, and do not meet the thin hind part of the postorbital {pt.o), which is cut through 

 close in front of the ascending process of the jugal (Plate XVI. fig. 1, pt.o,j). 



Section 13. — This section (Plate XVII. fig. 5) is through the large deep temporal 

 spaces and the fore part of the ear-capsule. The roof is partly membranous ; where it 

 is covered in above it is not by investing bone but by the bottom of a high wall growing 

 from the mdocranial roof, or supraoccipital {s.o) ; the roof-bone is another crest on 

 the top of that, a long distance from the cranial cavity. This latter part is thickened 



