306 Mr. 1). M. S. Watson on 



Tliis tongue is continued down below the articulation with 

 the paroccipital process as a flange standing out behind it ; 

 its continuation on the ventral surface forms a low ridge 

 just outside the par()cci[)ital process (fig. 3). External to 

 this ridge lies a large smoothly rounded groove which begins 

 at a roughened ridge crossing the bone just outside of the 

 paroccipital process, and curves upwards, outwards, and as it 

 approaches the top of the skull forwards, until it issues on 

 the side of the skull towards the top. 



The anterior border of the groove is formed by a mode- 

 rately stout j)latc of bone, which gives rise to a small in- 

 wardly directed process separating the end of the paroccipital 

 process from tliat of the pterygoid (Hg. 3). This plate of 

 bone, whose lower border is straiglit and horizontal in 

 position, bears two deep notches below, and has a triangular 

 depression on its anterior face ; these features are connected 

 with the fixation of the quadrate. 



]i]xternal to the outer and larger of the two notches tlie 

 lower surface of the bone is very strongly roughened and the 

 thin lower edge of the plate expands and is split for articu- 

 lation with the ji'gal. This plate, which carries the quadrate, 

 i.s continued u}nvards and forwards, being closely united 

 with the jugal until it ends about 1 cm. behind the orbit in a 

 point received in a deep groove in that bone. 



Outside the extreme posterior end of the jugal is another 

 jBange, forming the outer border of the groove on the 

 squamosal; this surrounds the posterior side of the jugal, 

 which is thus wedged into a slit in the former bone. 



The anterior face of the splint of squamosal, which runs 

 forward along the parietal, gives off a thin lamina, which 

 unites with the similar process of the periotic to cover the 

 groove leading from the ptcrygo-paroccipital foramen to the 

 post-temporal fossa. 



Ji/fjal. — The jugal is a very large bone whieh forms a large 

 part of the zygoma; it is surrounded by the squamosal 

 above and behind, and its extreme posterior end is of trian- 

 gular section and is received in a slit in the squamosal 

 (figs. 1 & 2). At the anterior end of tlie zygomatic an-h 

 it is produced outwards and downwards in a powerful 

 process. 



The ju^al apparently forms at least half of the border of 

 the orbit, running forward beneath it until it is overlapped 

 and suturally united with the laehrymal. This anterior part 

 of the jugal is united by a jagged suture with the maxilla 

 aloim the whole of its lower border ; it sends a palatal process 



