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Mr. D. M. S. Watson on Pleurosaurus and 



This vicAv has the great virtue of explaining tlie structure 

 of the skull aud the systematic position of the two reptiles 

 from the Lithographic Stone, Sauranodon and Pleurosaurus. 

 The structure of the skull of these types has hitherto only 



Fi-. 3. 



Restored dorsal aspect of the skull of Pleurosaurus yoldfussi, x 1. 



Ju., jugal; Lac, lachrymal; Mx., maxilla ; Na., nasal; P.Mx., pre- 

 maxilla; P.O., postorbital ; Pb.Fr., prefrontal; Qu., quadrate; 

 Qa.J., quadrato-jugal ; Sq., squamosal. 



been known from Lortet's descriptions of the Lyons material ; 

 these are difficult to follow, and rather vitiated by a pre- 

 conceived notion that the animals were like Sphenodon. A 



