264 PALAEONTOLOGY. 



the lower jaw, a nearly entire skull, fragments of the pelvis 

 and of two femora : in the fine-grained sandstone, vertebras, 

 ribs, and some bones of the scapular and pelvic arches are 

 imbedded. The bones present a very brittle and compact 

 texture ; the exposed surface is usually smooth, or very finely 

 striated, and of a light blue colour. The sandstones contain- 

 ing these bones occasionally exhibit impressions of footsteps 

 which resemble those figured in the Memoir by Murchison 

 and Strickland (Geol. Trans., 2d series, vol. v., pi. xxviii. fig. 

 1) ; but they differ in the more distinct marks of the claws, 

 the less distinct impression of a web, the more diminutive 

 size of the innermost toe, and an impression corresponding 

 with the hinder part of the foot, which reminds one of a hind 

 toe pointing backwards, and which, like the hind toe of some 

 birds, only touched the ground with its point. The footprints 

 are likewise more equal in size, with more regular intervals, 

 than those figured in the above-cited Memoir : they measure 

 from the extremity of the outermost or fifth toe to that of the 

 innermost or first rudimental toe, about one inch and a half. 

 They are the only footprints that have as yet been detected 

 in the new red sandstone quarries at Grinsill. 



As the fossil bones have always been found nearly in 

 the same bed as that impressed by the footsteps above de- 

 scribed, they probably belong to the same animal. In the 

 vertebras both articular surfaces of the centrum are concave, 

 and are deeper than in the biconcave vertebras of the ex- 

 tinct Crocodilians ; the texture of the centrum is compact 

 throughout. The neural arch is anchylosed with the centrum, 

 without trace of suture, as in most lizards ; it sends outwards 

 from each angle of its base a broad zygapophysis with a flat 

 articular surface ; the two anterior surfaces look directly 

 upward, the posterior ones downward ; the tubercle for the 

 simple articulation of the rib is situated immediately beneath 

 the anterior zygapophysis. So far the vertebra? of the 



