WEALDEN CROCODILES. 427 



at present known, it seems to have most claim to be received into the Amphicoelian 

 family of the Crocodilian order, and perhaps has the closest affinity in that family 

 to the Crocodilus Bollensis, Jaeger {Macrospondylus, 11. v. Meyer). 



Genus — Goniopholis, Owen 



This genus was determined, and so named, from the characteristic form of the 

 teeth, which had been discovered in the Wealden strata of Sussex. These are 

 remarkable, for the thick, rounded, and obtuse form of the crown, the enamel of 

 which is marked by numerous close-set and neatly defined longitudinal ridges ; two 

 of these, larger and sharper than the rest, traverse opposite sides of the tooth 

 from the base to the ape.x of the crown, midway between the convex and concave 

 lines of the curvature of the tooth ; the cement-covered, cylindrical base of tlie tooth 

 is smooth. Such teeth vary from a length of crown of 2 inches, with a basal diameter 

 of 1^ inch, to teeth of one third these dimensions. 



In the British Museum is preserved a slab of Purbeck limestone, with a portion of 

 both endo- and exo-skeletons of a crocodile, in the lower jaw of which are preserved 

 two teeth (PI. 7), proving the specimen to have been identical with the Goniopholis 

 of the Wealden strata. 



Goniopholis crassidens, Owen. ' Grocodilia,' Plates 7 — 13. 



Our knowledge of this remarkably well-defined Amphiccelian Crocodile has been 

 derived from a study of its fossil remains, obtained from deposits of the Wealden and 

 Upper Oolitic ])eriods. 



The first indication of the genus was given by detached teeth from the Tilgate 

 quarry, which presented a thicker and more robust form of crown than in other Saurian 

 teeth of that period, the proportions being rather those of the teeth of the Proccelian 

 Crocodiles andAlligators of the tertiary and modern times. From these, however, the 

 Wealden ones differed in the longitudinal ridges of enamel traversing the exterior of 

 the crown, which are numerous, close-set, and neatly defined. Two of the ridges, 

 larger than the rest, traverse opposite sides of the tooth, and in the larger specimens 

 fioni the base to the apex, being placed midway between the convex and concave out- 

 lines of the curve of the tooth (PI. 11, fig. 3) ; in the smaller teeth, which intervene 

 between the larger ones in the mandibular series, these opposite ridges are limited to 



