GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



269 



Calamopora polyraorpha, Gold. 

 Cyathocrinites pinnatus, Gold. 

 Orthocera, undetermined. 

 Nautilus, undetermined. 



As a considerable number of fossils are common to the 

 grauwacke in Europe and America, it is very desirable 

 that an accurate list of such species should be published 

 to assist the geological inquirer. From the tables of De 

 la Beche I have at present merely enumerated such 

 organic remains, adding a few which I have myself 

 identified. 



KOSSILS OF THE GRAUWACKE COMMON TO EUROPE AND 



AMERICA. 



Zoophyta — 6 species. 

 Radiaria — -1 species. 

 Conchifera — 10 species. 

 Mollusca — 8 species. 

 Crustacea — 3 species. 



The geographical distribution of the strata composing 

 the grauwacke group is exceedingly interesting^ inasmuch 

 as they are characterised by organic remains which indi- 

 cate that they originated in a climate of a far higher 

 temperature than exists at present in regions without the 

 tropics; for at the period when these mollusca enjoyed 

 life, the arborescent fern, and other vegetable forms now 

 imitated by the Flora of tropical countries, shaded the 

 soil in a burning clime, now swept by the blasts of a 

 polar winter, and whose altered vegetation is strongly 

 contrasted by those remains of plants indicative of the 

 unbounded exuberance which characterised the green 

 mantle of our globe in its earlier day. 



This uniformity of temperature over so vast an extent 

 of country, from central Alabama to the border of the 



