SAl r ROPTERYGIA. 



237 



are subequal, smaller than the maxillary teeth ; their crowns 

 are subhemispheric in P. laticeps, but in P. Andriani they 

 present a bent, pointed, prehensile character. In P. laticeps 

 the first maxillary tooth has a full oval crown, ^ lines by 4 

 in diameter ; the second measures 5j lines by 4 J lines in 

 diameter ; the third is subcircular, 8 lines in diameter, on the 

 right side. The palatal series begins on the inner side of this 

 tooth, and consists of two teeth on each side. The first tooth 

 (fl>.f) has a full elliptical crown, 10 lines by 8 ; the second 



Fig. 91 



A. Rkynchosaurus articeps 



B. Chelone longiceps, 0\v. 



C. Placodus laticeps, 0\v. 



0\v. ; Trias, Shropshire. 

 Eocene, Sheppey. 

 Trias, Bayreuth 



tooth (ib. g), developed in the broad pterygoid bone, presents 

 a full oval shape, 1 inch 9 lines by 1 inch 3 lines in diameter. 

 In Placodus gigas and P. Andriani the palatal teeth, three in 

 number on each side, are all of large size, slightly increasing 

 from before backwards ; they are situated close together, 



