THE PERMIAN PERIOD. 207 



pear to have been Chelonians (Tortoises and Turtles) ; but it 

 would not be safe to accept this conclusion as certain upon the 

 evidence of footprints alone. The Chelichnus Duncani, how- 

 ever, described by Sir William Jardine in his magnificent work 

 on the ' Ichnology of Annandale, ' bears a great resemblance 

 to the track of a Turtle. 



No remains of Birds or Quadrupeds have hitherto been 

 detected in deposits of Permian age. 



LITERATURE. 



The following works may be consulted by the student with 

 regard to the Permian formation and its fossils : 



(1) "On the Geological Relations and Internal Structure of 



the Magnesian Limestone and the Lower Portions of 

 the New Red Sandstone Series, &c. " ' Trans. Geol. 

 Soc., ' ser. 2, vol. iii. Sedgwick. 



(2) ' The Geology of Russia in Europe. ' Murchison, De 



Verneuil, and von Keyserling. 



(3) ' Siluria. ' Murchison. 



(4) ' Das Permische System in Sachsen. ' Geinitz and Gutbier. 



(5) 'Die Versteinerungen des Deutschen Zechsteingebirges. ' 



Geinitz. 



(6) ' Die Animalischen Ueberreste der Dyas. ' Geinitz. 



(7) 'Monograph of the Permian Fossils of England' Palaeon- 



tographical Society). King. 



(8) ' Monograph of the Permian Brachiopoda of Britain ' 



( Palseontographical Society). Davidson. 



(9) " On the Permian Rocks of the North-West of England 



and their Extension into Scotland " ' Quart. Journ. 

 Geol. Soc., ' vol. xx. Murchison and Harkness. 



(10) 'Catalogue of the Fossils of the Permian System of the 



Counties of Northumberland and Durham. ' Howse. 

 (n) ' Petrefacta Germaniae. ' Goldfuss. 



(12) ' Beitrage zur Petref aktenkunde. ' Munster. 



(13) 'Ein Beitrag zur Palaeontologie des Deutschen Zech- 



steingebirges. ' Von Schauroth. 



(14) ' Saurier aus dem Kupfer-schiefer der Zechstein-forma- 



tion. ' Von Meyer. 



(15) 'Manual of Palaeontology.' Owen. 



(16) 'Recherches sur les Poissons Fossiles. ' Agassiz. 



