462 KR'IIAKD SWAXX LULL ON 



problems of synonymy, but above all for his admirable Bibliography and catalogue of the 

 fossil Vertebrata of North America (:02) which proved a great aid in the preparation of 

 the l)ibliography. 



The writer is also under obligations to Prof. A. Smith Woodward, of the British 

 museum, for a superb photograph of Chirotheriuni ti'acks, to Prof. C. H. Hitchcock for 

 further notes on some of his species of footjirints, to Professor Emerson for notes on the 

 geology of the Connecticut valley, and to many others wlio, by their suggestions, have 

 aided the work. Finally, to my fi-ieiid and teacher. Professor Osborn, my gratitude is 

 especially due for his sympathetic advice and criticism and for the great fund of knowl- 

 edge concerning these early forms, of which he was ever ready to impart. 



Historical Sketch. 



An excellent resume of the whole progress of ichnology has been given by C. 

 Winkler in his "Histoire de Tichnologie " ('86). but a sketch of the development of the 

 science, especially in this country, may not be out of place. 



Discoceri/. — Footprints were first discovered in 1812 or 1813 in the Bunter sand- 

 stone, at Dimifries, Scotland, but not until 1828 was the first description, that written by 

 Duncan, o-iven to science. The famous Chirotheriuni footprints from Hildburghausen, in 

 Saxony, were first mentioned in 1834 in a communication by Reinhard Bernhardi to the 

 Neues iahrbuch fiir mineralogie, and were first described by J. Kaup in the same publica- 

 tion in 1835. 



Another very important discovery was that of the Storeton footprint quarry near 

 Liverpool, England, first described by Cunningham, Yates, and Edgerton in the London 

 and Edinburgh philosophical magazine, in 1838. This locality has yielded an interest- 

 iuo- Chirotherium of a later stage of evolution than C. harthi, and in addition there are 

 numerous tridactyl tracks of which a study is yet to l)e made. 



Before the discovery of the Storeton remains, those of the Connecticut valley had 

 t)een found, their true nature recognized, and the first notice recorded in the American 

 journal of science and arts, in 1836. Winkler says, in speaking of the former discoveries: 

 "' By these impressions of divers feet, the existence of reptiles and of amphibians which 

 have left their traces in the rocks, has been proved; now it is the impressions of the feet 

 of birds which have been found in the new red sandstone of Massachusetts." 



While Hitchcock was apparently the fii'st to treat the Connecticut valley impressions 

 from a scientific point of view, yet to Dr. Deane ('44b), of Greenfield, Massachusetts, 

 l)elongs the credit of discovery, though he believed the tracks to lie those of a turkey, and 



