NATURAL HISTORY 



companied with slate clay, bituminous slate, and other 

 rocks, all of which frequently contain petrifactions of bi- 

 valve shells, and impressions of plants. The shells re- 

 semble those met with in the alpine limestone, and also 

 in the Jura limestone ; and the vegetable impressions 

 are of lycopodiums and ferns, resembling those found in 

 the old coal formation. But, besides these, we observe 

 remains of plants of the palm tribe, some of which re- 

 semble the carica papaya, a native of Senegal. 



III. Second or variegated Sandstone Formation. 

 Third Sandstone Formation. 



The second sandstone rests upon the first limestone and 

 gypsum, and also upon coal,^ but the position of the third 

 sandstone has not been accurately ascertained. The 

 following are some of the petrifactions mentioned by au- 

 thors as occurring in them. 



Encrinites trochitiferus. Schlottheim. Brunswick. 

 Dentalites striatus. Schlottheim. Mecklenburg. 

 Trochilites scheuchzeri. St. Gallen. 

 Turbinites torquatus. Knorr. Neufschatel. 



regensbergensis. Knorr. Regenberg, near 



Blankenburg. 



australis. Schlottheim. France. 



Muricites volutinus. Bourg. T. 34. F. 223. St. Gallen. 



nisus. Bourg. T. 34. F. 226. St. Gallen. 



assimilis, Bourg. T. 24. F. 228. St. Gallen. 



Bullites reticulatus. Bourg. T. 37. F, 240, St. Gallen. 



senilis. Bourg. T. 87. F. 250. St. Gallen. 



Pectinites punctatus. Volkm. Sites, subterr. T. 23 F. 3. 



* In the lower parts of Dumfries- shire it rests upon the coal forma- 

 tion. 



