OF ARTS AND SCIENCES: DECEMBER 10, 1862. 91 



was a quadruped with unequal feet and long heels to its hind feet ; as 

 is still further proved by the trace of a tail. The animal seems to 

 have rested for a moment upon all its feet ; and then it rose and went 

 forward again upon the toes of its hind feet ; in other words, it was 

 digitigrade ; and Professor Hitchcock suggested that several of these 

 ancient animals must have used only the toes of their hind feet in 

 walking, and rarely brought their fore feet to the ground. 



We must not hastily conclude from these facts that all the tracks of 

 apparently biped animals in the valley are really those of quadrupeds, 

 which proposition Professor Hitchcock attempted to prove in a paper 

 read before the American Association for the Advancement of Sci- 

 ence, at their Newport meeting, and published in their Proceedings. 

 Moreover, he had attempted to show in his Ichnology, that the facts 

 as to the number of phalanges in the Anomcepus might be explained 

 without destroying the evidence of an ornithic origin in the fourteen 

 thick-toed bipeds : for other slabs in the cabinet had taught the same 

 facts, though less distinctly than the specimen above described. The 

 facts, however, do show us that the quadrupeds of sandstone days 

 had strong ornithic characters, and they justify the conclusion, that, if 

 none of the animals that made the tracks were veritable birds, they 

 approached very near them in chai-acter. Every department of pala3- 

 ontology teaches that many of the ancient animals possessed inter- 

 mediate characters between the less perfect races that preceded and 

 the more perfect ones that followed, so that we should not think it 

 strange if Ichnology teaches the same, as it does most decidedly; 

 and it may be that, so nearly balanced sometimes are the characters 

 between birds and reptiles, that from tracks alone we may never be 

 able certainly to determine to which class the animals belonged. 



The recent discovery in the lithographic quarries at Solenhofen, in 

 Bavaria, of the Gryphosaurus, is a striking illustration of this subject. 

 For, according to the discoverer, it was a feathered fossil reptile, 

 feathered on the fore legs, and with a radiate fan at the extremity of 

 the tail. Its osteology, also, in some important respects, corresponds 

 to that of birds. Indeed, it was stated by a member of the Academy, 

 that Professor Owen still maintains that this animal was a bird, in 

 opposition to the German anatomists, Wagner and Meyer. But if 

 such eminent authorities differ, when even the skeleton is before them, 

 much more may we hesitate when we have only tracks. 



It may be, however, that hght may come from Ichnology, which 



