180 MARINE REPTILES OF THE OXFORD CLAY. 



B. Forms in which the surface of the cranial hone is more or less sculptured with pits and 

 grooves. 



a. Narrow-skulled forms. 



3. Metriorhynchus superciliosum. — A narrow-skulled form in which the surface of the 



frontal is sculptured with sharply defined pits. The frontal extends forwards nearly to 

 the level of the anterior angle of the prefrontals, and its length in front of the 

 temporal fossse is considerahly greater than the least width between the orbits. About 



25 teeth in each maxilla. (Text-fig. 73, C.) 



4. Metriorhynchus moreli. — A narrow-skulled form in which the frontal bears a sculpture of 



shallow and, as it were, partly obliterated pits ; its anterior angle does not extend 

 forwards to the level of the anterior angle of the prefrontals, and its length in front of 

 the temporal fossffl is about equal to the least width between the orbits. About 



26 teeth in each maxilla. (Text-fig. 73, D.) 



b. Broad-skulled forms. 



5. Metriorhynclius cultridens. — Skull with comparatively short rostrum, in which the nasals 



are separated from the premaxillse by a distance about equal to a quarter of their own 

 length. Supraorbital notch an open continuous curve ; teeth smooth and with strongly 

 compressed crowns ; about 20 teeth in the maxilla. (Text-fig. 73, E.) 



6. Metriorhynchus brachyrliynclius. — Skull with short rostrum, in which the nasals meet or 



nearly meet the preinaxillse. The supraorbital notch forms a sharp angle, and a line 

 joining the outer angles of the prefrontals passes behind the posterior angle of the 

 nasals. About, 18 teeth in the maxilla. (Text-fig. 73, F.) 



7. Metriorhynchus durobrivense. — Skull broad with a short rostrum, in which the nasals do 



not quite reach the premaxillse. A line joining the outer angles of the prefrontals 

 passes through the hinder angle of the nasals. About 13 teeth in the maxilla. 

 (Text-fig. 73, G.) 



MetriorhyncllUS SUpercillOSUin, de Blainville, sp., ex Conybeare MS. 

 [Plate IX. figs. 1, 2 ; text-figs. 55-56, 61 A, 67, 6S, 69 A, 70, 73 C] 



1853. Crocodilus supcrciliosus, de Blainville, Mem. Soc. Linn. Normandie, vol. ix. p. 114 (ex 



Conybeare, MS.). 

 186*7. Teleosaurus superciliosus, Deslongchamps, Bull. Soc. Linn. Normandie, [2] vol. i. p. 149. 

 1867. Metriorhynchus superciliosus, E. E. Deslongchamps, Notes Paleontologiques, p. 118. 

 1869. Steneosaurus dasyceps, Seeley, Index to the Fossil Remains of Aves etc. in the Wood- 



wardian Museum, p. 140. (No de.-cription.) 

 1904. ? Metriorhynchus jaeheli, Schmidt, Zeitschr. deutsch. geol. Gesell. vol. lvi. p. 97, pis. xi., xii. 



Type Specimen. — A skull, a cast of which was sent by Conybeare to de Blainville, 

 who found it identical with specimens from the Oxfordian Clay of Dives and Vaches- 

 Noires in Normandy, and adopted Conybeare's manuscript name for the species. 



The skull (PL IX, fig. 1 ; text-figs. 55-56) and mandible of this species, which is 

 that most commonly found in the Oxford Clay of both England and France, have 

 been described in great detail by E. E. Deslongchamps in his ' Notes Paleontologiques ' 



