FROM THE LOWER LIAS OF CHARMOUTH. 



443 



drate, not extending more than 1*5 inch beyond the posterior edge 

 of the condyle. 



The quadrate appears to be directly continuous with the squa- 

 mosal on each side ; and the latter bones are prolonged upwards into 

 a process which, viewed from behind, has a somewhat sabre-like out- 

 line, with the convexity outwards. Both these suprasquamosal 

 processes are broken at the distal end, so that their junction over the 

 parietal (a characteristic Chameleon feature seen in most Plesio- 

 saurs) is not here observable. 



Superior Aspect. — Most posterior is the previously mentioned axis 

 and atlas vertebral mass ; then succeed in front the approximated 

 ends of the broken suprasquamosal processes. The parietal comes 

 next, a pent-roof-like bone, 5-75 inches long, compressed for the 

 anterior three quarters of its length into a strong median crest, 

 along which the persistent sagittal suture extends, expanding ante- 

 riorly into the foramen parietaU 0*3 inch wide, in front of which the 

 parietal ends. Behind, the parietal is expanded into a form like 

 the bowl of a spoon, the bowl being supposed turned with the con- 

 vexity upwards. 



The next bones in front are the frontals, longitudinally ridged in 

 the middle, smooth at the sides, and separated by a median suture, 

 which is slightly more open in the middle of its length than at the 

 ends*. A splintery suture joins the frontals to the nasals, which 

 are short longitudinally striated bones, not by any means clearly 

 defined in front from the posterior prolongations of the praemaxillse. 

 The praemaxillse, 9 or 10 inches long, are separated for their whole 

 length by a simple suture ; posteriorly they are smooth, or only 

 faintly wrinkled, but in front much roughened, probably for attach- 

 ment of integument. 



From the parietals a process is given off on each side of the fora- 

 men parietale, and continues backwards as far as the middle of the 

 lateral margin of the bone ; in uncrushed skulls this process is a 

 plate of bone standing out nearly at right angles to the body of the 

 parietal ; its parallelism in this case must be due to compression. 



Lateral Aspect. — On the left side the upper jaw is 14*3 inches 

 long ; and the anterior 4*3 inches is furnished by the prsemaxilla ; 

 this bone joins the maxilla along a line which runs obliquely 

 upwards and backwards, to end just above the anterior nares. 

 The maxilla is an irregularly triangular bone. Its base (10" long) 

 furnishes the margin of the upper jaw ; its anterior side bounds the 

 prsemaxilla ; its posterior side, just behind the apex, furnishes the 

 lower anterior boundary to the external nostril, and further down 

 the lower anterior margin of the orbit (being excluded from the upper 

 part of it by the lacrymal and prefrontal bones, here badly defined) ; 

 still further downwards and backwards it meets the jugal, by 

 which it is excluded from the posterior half of the lower boundary 

 of the orbit ; and along and beneath this bone it extends to its 



* This appears to indicate a fossa corresponding to that on the frontal suture 

 of the Lizard's skull, interpreted by Professor Parker as " the scarcely-closed 

 anterior fontanelle' of Clarias." — Phil. Trans, clxx., 1879, p. 598. 



