DEVELOPMENT OF THE SKULL IN THE LACERTILIA. 
599 
A sharp bony wedge, the second supra-temporal (s.t.~) is jammed in between the 
squamosal and the parietal horn behind (fig. 4), its thick end rests upon the “ parotic 
process ” (op.), its sharp top runs inwards as well as upwards. 
In many kinds (Monitor, Iguana, Lcemanctus, Cyclodus, &c.), the first supra- 
temporal is wanting, the second is constant, and even exists in the Snakes, whilst they 
are young (“Snake’s Skull,” Plate 31, fig. 7). 
These four bones—the post-orbital, squamosal, and first and second swpra-temporals— 
are the temporal counterparts of the double row of super-orbitalsthe squamosal and 
first supra-temporal are the outer row, and the others form the inner; properly 
speaking these are all supra-temporals. 
The first and last of the sub-orbital series of the bony fish re-appear in this Lizard ; 
the fifth or down-turned super-orbital (or outer post-orbital) scute is the same as the 
suspensory piece of the chain, behind ; the front attaching bone is here the small 
perforated lachrymal (l.). 
This bone is very constant in the “ Lacertilia,” but is always small. It lies on the 
maxillary, and is touched by the point of the jugal (mx.,j.) ; these bones and the two 
foremost super-orbitals overlap the Cuvierian “ prefrontal,” a conchoidal deep scute 
(figs. 1 and S,p.f.). 
This bone keeps free on the surface of the nasal wall, as it does in the “ Urodeles 
in them I have called it ecto-ethmoid : either name fits it. 
In Ganoid and Osseous Fishes, and in Birds, this bone is represented by a deeper 
layer: an “ ectostosis,” which ossifies the ecto-ethmoidal or prefrontal mass. 
Where the skull closes in behind the nasal sacs, there should be a median bone, a 
“ meso-ethmoidalit exists as a parostosis in Iguana tubercidata, as in some Fishes 
(e.g., Salmo) ; in Clarias it is dermosteal, but in the Cyprinoids, and generally, in the 
“ Anacanthini,” and “ Acanthopteri,” it is an ectosteal plate ossifying the meso- 
ethmoidal cartilage. 
So it is in the Ostrich and his relations, but in other Birds it has no separate 
beginning (“ Ostrich’s Skull,” Plate 8 ). 
In Birds the nasal processes of the pre-maxillaries keep the nasals apart; in this 
Lizard, and even in the Iguana, where there are two azygous plates, the nasals meet. 
They are supero-lateral bones, notwithstanding, as all the Holostean Ganoids, and 
Teleosteans, show ; the Amphibia also teach this. 
Here in Lacerta the nasals meet in their hinder half (Plate 42, fig. 1 , n.) ; they are 
separated from the prefrontals by a spike of the maxillary on each side, and from each 
other in front by the nasal process of the single premaxillary. 
With that process they form a sort of pentagon ; they make a straight suture across, 
with the frontals, and overlap the alinasal cartilage, antero-externally. 
Inside the alinasal cartilage, flooring the nostril, another scale is found, the septo- 
maxillarv (Plate 43, fig. 1, s/rnx.) ; this little conchoidal sub-mucous scute lies upon the 
nasal gland ( n.g .), and flanks the septum nasi ( s.n .). 
mdccclxxix. 4 II 
