188 MARINE EEPTILES OF THE OXEORD CLAY. 



R. 2062. Basioccipital, portions of mandible, odontoid, axis, and the centra of four other cervical, 

 and four dorsal vertebrae of a young individual. 



R. 2077. Several anterior chevron-bones. 



R. 2062 a. Nearly uncrushed anterior portion of mandibular symphysis (? of M. moreli). 



Metriorliynclius aff. moreli, Deslongchamps-. 



[Plate IX. figs. 3, 4 ; text-figs. 57, 62-64, 71, 72, 73 D.] 



The type specimen of M. moreli is a skull from the Oxford Clay of Villers-sur-Mer in 

 Normandy. It was described and figured in detail by E. E. Deslongchamps in ' Notes 

 Paleontologiques ' (1867), p. 320, pi. xxi. figs. 4 & 5, pi. xxii. figs. 1 & 2. The 

 specimens from the Oxford Clay of Peterborough, here referred provisionally to this 

 species, resemble Deslongchamps's type in many respects, but at the same time present 

 some differences. The sculpture of the frontal, which appears as if half obliterated, 

 and the comparative massiveness of the snout, are points of similarity ; the frontal 

 also, in both the Oxford Clay specimens and the type, are shorter in front of the 

 temporal fossa than in M. swperciliosum, with which alone this form is likely to be 

 confused ; at the same time, in the specimens here described this shortening of the 

 frontal is carried further than in the type, their anterior extremity being at a greater 

 distance behind the anterior angles of the prefrontals. The length of the frontal 

 anterior to the temporal fossae is about equal to the least width between the orbits 

 while in M. superciliosum it is considerably greater. The bar of the frontal between 

 the temporal fossae is narrow. The distance between the anterior angle of the nasals 

 and the posterior point of the premaxillae is about equal to a third of the len»th of 

 the former. 



The teeth are less sculptured than in 21. superciliosum, the outer, somewhat flattened 

 side of the crown being almost entirely smooth. There are twenty-six teeth in each 

 maxilla, two more than are given by Deslongchamps for the type specimen. 



The similarity between the type and the Peterborough specimens being so °reat, it 

 has been thought best to refer them provisionally to the same species: the differences 

 may indicate a local race or variety. 



R. 2054 (Leeds Coll. 37). Skull (PI. IX. fig. 3), mandible, atlas, axis, and four other cervicals 

 (the last being wanting), eighteen dorsals (text-fig. 62), two sacrals (text-figs. 63, 64), 

 and twenty-eight caudals, numerous ribs and chevron-bones, ilium, ischium, pubes 

 (text-figs. 71, 72), tibia, fibula, and numerous bones of the hind foot. The atlas and 

 axis were figured and described by Hulke in Proc. Zool. Soc. 1888, p. 418, pi. sviii. 

 fig. 1 ; in this specimen a well-developed diapophysis is borne on the base of each 

 half of the neural arch of the axis. 



