132 



BRITISH FOSSIL REPTILES. 



parts of the four extremities, together with the dorsal and part of the ventral 

 series of dermal bones. The entire length of the skeleton, follomng the curvature 

 of the spine, is 15 feet 6 inches, to which may be added 2 feet 6 inches 

 for the lost snout. The cranium posteriorly is broad, depressed, and square- 

 shaped ; it begins to contract anterior to the orbits, and gradually assumes the 

 form of the narrow depressed snout : the converging sides of the maxillee are con- 

 cave outwardly. The zygomatic spaces are quadrilateral, longer than the upper 

 temporal openings, and these are longer in the axis of the skull than transversely. 

 The orbits are subcircular ; they look upwards and slightly outwards ; their 

 margins are not raised, and their interspace is slightly concave. The parietal 

 bone is relatively longer than in the Gavial, and sends up a longitudinal median 

 crest, from the posterior part of which a strong process extends on each side 

 outward, and curves slightly backward, parallel with the ex-occipitals, to join the 

 mastoid and tympanic bones, the latter of which expands as it descends to form 

 the joint for the lower jaw. 



Breadth of posterior part of skull 



Length of parietal crest .... 



Breadth of the interorbital space 



Antero-posterior diameter of the middle of tympanic pedicL 



Vertical diameter of orbit .... 



Antero-posterior of orbit .... 



Prom lower margin of orbit to alveolar border 



the entire length of the skull 



From these dimensions it may be calculated tha 

 must have exceeded 4 feet 6 inches. 



The skull of one of the Caen Teleosauri measures 3 feet 4 inches, whence Cuvier 

 calculates the entire length of the animal at near 15 feet. The Whitby Teleosaur 

 agrees with the Caen species, and differs from the Gavial in the following particulars 

 {Grocodilia, PI. 1, vol. ii). The anterior frontal is less extended upon the cheek ; 

 the lacrymal is much more extended, and is larger at its base ; the malar bone is 

 more slender. The post-frontal, which separates the temporal from the orbital 

 cavities, is much longer and narrower. The parietal and occipital crests each form 

 a thin trenchant plate, and are not flattened above. The mastoidean angle is not 

 uninterruptedly united with the back part of the articular process of the tympanic, 

 it is separated from it by a large depression, which is overarched by a trenchant 

 crest belonging to the exoccipital. The mastoid has a concavity at its descending 

 part, of which there is no trace in the Gavial. The indentation between the 

 articular process of the tympanic and the tuberosity of the basioccipital is much 

 smaller than in the Gavial, and the basilar tuberosity projects downwards in a less 

 degree. The pterygoid ala is not expanded externally, as in all Crocodiles, but is 

 contracted by a large fissure at the part where it goes to unite itself to the bone ; 



