240 PALEONTOLOGY 



the above order, genus, and species of reptile have beei: based 

 are from the new red sandstone (trias) of Shropshire. They 

 occur at the Grinsill quarries, near Shrewsbury, in a fine- 

 grained sandstone, and also in a coarse burr-sandstone ; in the 

 latter the writer found imbedded some vertebra', portions of 

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

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

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

 imbedded. The bones present a very brittle and compacl 

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

 striated, and of a light blue colour. The sandstones containing 

 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 Hie 

 hinder part of the foot, which reminds one of a hind toe point- 

 ing 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, and likewise in their 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 rudiment al 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 described, 

 they probably belong to the same animal. In the vertebra' 

 both articular surfaces of the centrum are concave, and are 

 deeper than in the biconcave vertebrae of the extinct Croco- 

 dilians ; 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 immediately expands 



