39b* 



Prof. J. W. Judd. 



[Dec. 10, 



Edinburgh, who, at my request, proceeded to examine the specimen. 

 A second example of the same genus has since been discovered, and I 

 trust that ere long a full description of this interesting addition to 

 our British fossils will be given by Dr. Traquair. 



In addition to these facts, I may add that casts of teeth, undis- 

 tinguishable from those of Geratodus, were some time ago obtained 

 from the Spynie quarries. 



The present state of the palseontological evidence concerning the 

 age of the beds then is as follows. The strata have yielded the 

 remains of no less than four orders of reptiles, all of them belonging 

 to forms very different to any which have been found in Palaeozoic 

 rocks. The Lacertilia are represented by Telerpeton, Hyper odapedon, 

 and an undescribed form ; Crocodilia by Stagonolepis ; Dinosauria 

 by an undescribed skeleton and possibly by Dasygnathus ; and Dicy- 

 nodontia by two individuals belonging to the type genus of the order. 

 In addition to these we have a great number of footprints differing 

 so greatly in form and size that they must probably have been made 

 by creatures of very different proportions and organisation. Professor 

 Huxley in his later researches on the subjects of these footprints* points 

 out the necessity of the greatest caution in any attempts to correlate 

 them with either of the reptiles whose skeletons have been found in 

 the same formation ; indeed, he hesitates as to whether the most per- 

 fectly preserved of them should be referred to Amphibians or to 

 representatives of one or other of the orders of Reptilia. Among 

 the less perfect of the markings in these and other rocks of the 

 Elgin district, there are not a few concerning which I have serious 

 doubts whether they are to be ascribed to vertebrate animals at all. 



It will be seen from this summary that the palseontological evidence 

 in favour of the Triassic age of the Elgin sandstones is now absolutely 

 overwhelming. Besides the remains of Hyp erodapedon and Dicynodon, 

 genera which appear to be confined to Triassic strata, in districts so 

 widely separated as South Africa, India, the Ural Mountains, and the 

 British Islands, we have Stagonolepis, a crocodile with Mesozoic 

 affinities, the highly organised Telerpeton, and Dinosaurs ; the last 

 mentioned having never been found in any rocks older than Trias. 

 Geratodus, too, has usually been regarded as having commenced in 

 the Trias, though it must be admitted that difficulty may exist in 

 separating the cast found at Spynie from Gtenodus, which occurs in 

 the Carboniferous, or Dipterus, which occurs in the Devonian. 



There are certain facts concerning the distribution of these fossils 

 in the formation where they occur, to which it may be instructive to 

 refer as bringing out into strong relief the imperfection of the 

 geological record. The footprints, which are so abundant at Cum- 

 mingstown and Hopeman, would appear to have been seldom, if ever, 

 * "Mem. G-eol. Survey," Monograph III, pp. 45-51. 



