﻿lxxvi PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Mr. Logan ; and the Hunterian Professor has had the kindness to 

 communicate to me the following description : — 



" The impressions are more numerous in regular succession than 

 any that have been previously discovered ; so that the evidence of 

 their having been made by successive steps, afforded by this suc- 

 cession of corresponding prints at regular intervals, is the strongest 

 we possess. They are in pairs, and the pairs extend in two parallel 

 linear series with a groove midway between the two series. The 

 outer impression of each pair is the largest, and it is a little behind 

 the inner one. Both are short and broad, with feeble indications of 

 divisions at their fore part. They succeed each other at intervals 

 much shorter than that between the right and the left pair. 



" The median groove is well-defined and slopes down more steeply 

 at its sides than towards the bottom, at some parts of the track. I 

 conclude from these characters that the animal which left the track 

 was a quadruped, with the hind-feet larger and wider apart than the 

 fore-feet ; with both hind- and fore-feet very short, or impeded by 

 some other part of the animal's structure from making any but 

 short steps ; that the fore and hind limbs were near each other, but 

 that the limbs of the right and those of the left side were wide apart : 

 consequently, that the animal had a short but broad trunk, supported 

 on limbs either short or capable only of short steps ; and that its 

 feet were rounded and stumpy, without long claws. 



" As to the median impression, that may be due either to a thick 

 heavy tail, or to the under surface of the trunk, dragged along the 

 ground. The shape of the body and the nature of the limbs, indi- 

 cated by the above-described characters of the steps, accord best 

 with those of the land or freshwater tortoises, and the median 

 groove might have been scooped out by the hard surface of a pro- 

 minent plastron. 



" The disproportion in the size of the fore- and hind-feet is such 

 as we find in some existing Terrapenes, e. g. the Ernys geographical 

 R. Owen— Letter to Sir C. Lgell, March 18th, 1851. 



