126 
MR. W. K. PARKER ON THE STRUCTURE AND 
roof-bones, viz. : the parietals and frontals, are now only one pair (fp). the coronal 
sutures having early disappeared. 
This double fronto-parietal tract is twice as wide over the occiput as over the orbits ; 
its hind margin, like its front margin, is almost straight, but the edge on each side 
uniting it with the squamosal (sq.) converges forwards, and is a roughly dentate 
suture—this answers to the squamous suture in Man. 
Each squamosal (sq.) is a bone with a descending and retreating handle, and a 
roughly pentagonal blade; these are the temporal and pre-opercular regions of the 
bone. 
The pointed fore end of the temporal plate —its postorbital projection—is united by 
suture with the upper edge of the maxillary (tig. 3, mx.); this is a sinuous suture, and 
behind it the edge of the squamosal rises and falls twice : first outside the pterygoid 
(pg .), and then over the “annulus tympanicus,” forming the ledge under and to which 
it is attached (fig. 3). 
The preorbital rim is formed by the nasals ( n .), these are very large, about half the 
size of the fronto-parietals. 
In front of their concave preorbital edge they form a large descending pedate 
process (fig. 3), which rests upon, and is united by suture with, the fore end of the 
maxillary, on each side. 
The median spur of each nasal is blunt, and the fore edge has a large round notch, 
exposing the nasal roof ( al.n .), which is itself notched for the nostril (e.n.). 
The main roof-bones dip into the orbit (fig. 3 ,fp.), forming an orbital plate. 
The arcuate premaxillaries ( px. ) form a divided but strong key-stone to the great 
arch of the face; their palatine and nasal processes are well developed and normal. 
The maxillaries (mx.) are notched in front, where they articulate — without the inter¬ 
vention of a septo-maxillary—with the premaxillary. 
The lower dentary edge of the bone is gently arched, and the jugal process reaches 
as far back as the tegmen tympani (t.ty.). Half the depth of the side of the skull is 
formed by the maxillary, whose edge is cut away below the eye, and is again deeply 
notched behind the postorbital suture; it then becomes the rapidly lessening jugal 
process. 
The quadrato-jugals (q.j.) are one-third the length of the maxillaries, but are only 
the size of the jugal processes ; they strongly bind on the lower part of the squamosal 
(fig. 3), and are grafted largely on the quadrate, and there pass under the squamosal; 
this is best seen in the palatal view (fig. 2). 
That view also shows how large the palatal plate of the maxillary is, especially 
where it is locked to the pterygo-palatine arch ( pg.). 
The parasphenoid (figs. 2 and 3, pa.s.) is a large bone, and reaches to within a short 
distance of the foramen magnum, behind, and to the beginning of the unossified 
septum nasi in front. 
It projects by a very obtuse angle behind, its “ basi-temporal wings ” are broader 
