102 PROF. W. K. PARKER ON THE STRUCTURE OF 
6. Endocranial modifications in the Chameleon’s skull : 
14. The huge high supraoccipital crest. 
15. The absence of the rudiment of a cochlea, and of the fenestra rotunda. 
16. A very small and simple alisphenoid, instead of the normal basketwork of car- 
tilage and bone. 
17. The orbito-nasal septum agrees with many in having the membranous space 
enclosed (as a fenestra), and not open (as a notch), as in Lacerta. 
18. There is no cranio-facial fenestra between the perpendicular ethmoid and the 
septum nasi. 
19. The ali-ethmoidal cartilages are notched for the nasal glands; and there is no 
fenestra, right and left, in the ali-septal roof. 
20. There is no free or confluent labial cartilage running between the snout and the 
upper surface of the vomer, as in Lacerta ; but the ali-nasal annulus is much more evi- 
dently a confluent (valvular) labial, corresponding to the owter upper labial of the meta- 
morphosed Frog and Toad. 
c. Modifications of visceral arches in the Chameleon : 
21. There is no epipterygoid—a part which exists in all other Lacertilia known to 
me, is largest in Hatteria, and is present in all known Chelonia. 
22. The pedicle of the quadrate is a very distinct process from the otic process ; it is 
much broader than in the Chelonia, but, as in them, has the tip unossified. 
23. The columella keeps within the quadrate, has not a bifurcated supra-stapedial 
process, has no infrastapedial, and is not functional; there is no cavum tympani. The 
hyo-branchial apparatus is very unlike that of the typical Lizard. 
24, The hypohyals are quite distinct from the basal bar and from the ceratohyals ; 
the latter are not dilated below; both hypo- and ceratohyals are (normally) unossified. 
25. The basi- or glossohyal is as long as the skull, is highly ossified, and has a small 
unossified segment at its fore end and a non-segmented basibranchial process behind. 
26. The ceratobranchials are well ossified; they have no upper or epibranchial 
segment, as in Lacerta ; there are no hypobranchial processes, or thyro-hyals, behind and 
within them proceeding from the basal bar, which is narrow and rounded at the end. 
Comparison of the CHaMELEON’s SKULL with that of the AMpHIBIA and the CuELonta. 
The skull of the Chameleon, in differing so much from that of the other Lacertilia, 
does not, at the same time, approximate to that of other types below, aside of, or above 
its own family. 
The Chameleon’s skull resembles that of those Anura which have a columella but 
no “‘cavum tympani,” and also agrees with them in having neither a cochlea nor a 
fenestra rotunda. It agrees with the Chelonians in having a single vomer and no 
septo-maxillaries, and in having a crested supraoccipital, and with the Ophidia and 
Crocodilia in having no epipterygoid. 
