WEALDEN CROCODILES. 433 



Genus — Suchosaukos,* Owen. 

 SuCHOSAURUS ciLTRiDENS, Owcu. ' CrococlHia,' PI. 5. 



In the Wealden formations have been found detached teeth and vertebrae, indicat- 

 ing the existence, at that period, of a large Amphicoelian Crocodile specifically and 

 generically distinct from the Goniopholis ; for, since the discovery of associated bones 

 and teeth of the latter genus have made us acquainted with its vertebral characters, 

 the other remains, upon an exhaustive analysis of the reptilian fossils of the Wealden 

 series, leave only the form of Saurian tooth (PI. 5, fig. 4) wherewith to associate 

 the equally peculiar form of Saurian vertebra (Pi. 5, fiiis. I — 3). This vertebra is 

 readily distinguishable, by the length of the centrum and the compressed, wedge- 

 shaped character of its middle part, from all other known Saurian (Dinosaurian or 

 Crocodilian) vertebrae of the Wealden period. The specimen is No. i^^is' Mantt-llian 

 Collection of Wealden fossils in the British Museum (PI. 6, figs. 1, 2, 3), and is the 

 body of a dorsal vertebra, with both articular extremities slightly and equally concave ; 

 though narrower at the middle than at the ends, it is more uniformly compressed than 

 in other Crocodilian vertebrae, the sides converging to an inferior obtuse ridge, which 

 is very slightly concave in the antero-posterior direction. The sides are not flat in 

 the vertical direction nor slightly concave, as in many of the Iguanodon's vertebrae, 

 to which the present form approximates ; but are gently convex, so that a pencil laid 

 vertically upon the side touches it only by its middle. A more decided difference 

 between the present Crocodilian vertebrae and those of the Iguanodon is, that the 

 former are longer in proportion to their height and depth. The external surface 

 at the middle of the body of the vertebra is very finely striated, so as to present a 

 silky appearance; near the margins it is sculptured by coarse, longitudinal grooves 

 and ridges. 



The base of the neurapophysis (ib., fig. 3, b) which, when anchylosed, leaves 

 an evident trace of the suture, is nearly equal in length with the body of the vertebra 

 (ib., a) ; it does not wholly include the spinal canal, but leaves the impression of 

 the lower third of that canal upon the upper surface of the centrum. On the 

 outside of the neurapophysis are two slightly developed, broad, obtuse, ridges 

 converging towards each other from the outer side of eacii angle or end of the base 

 of the neurapophysis ; the ridge corresponding with the posteuior of these in the 

 Iguanodon's vertebra rises more vertically, and is in higher relief. The neurapo- 

 physial suture slightly undulates in its horizontal course, and rises in the middle 

 instead of descending upon the centrum, as in the Plesiosaurs. 



* Greek liiv)^ns, an Egyptian name of the Crocodile, and aavpos, lizard. 



