90 THE SIORY OF THE EARTH AND MAN. 



harder calcareous corals stand out in relief. Many 

 branches of these zoophytes project from their erect 

 stems precisely as if they were living. Among other 

 species I observed large masses^ not less than five 

 feet in diameter, of Favosites Gothlandica, with its 

 beautiful honeycomb structure well displayed. There 

 was also the cup-shaped Gyathophyllum, and the 

 delicate network of Fenestella, and that elegant and 

 well-known European species of fossil, the chain coral, 

 Gatenipora escharoides, with a profusion of others which 

 it would be tedious to all but the geologist to enume- 

 rate. Although hundreds of fine specimens have 

 been detached from these rocks to enrich the museums 

 of Europe and America, another crop is constantly 

 working its way out under the action of the stream, 

 and of the sun and rain in the warm season when 

 the channel is laid dry.''* These limestones have 

 been estimated to extend, as an almost continuous 

 coral reef, over the enormous area of five hundred 

 thousand square miles of the now dry and inland 

 surface of the great American continental plateau. 

 The limestones described by Sir Charles are known 

 in the Western States as the " Clifi" limestone.'^ In 

 the State of New York and in Western Canada the 

 " Corniferous limestone,'' so called from the masses 

 of hornstone, like the flint of the English chalk, 

 contained in it, presents still more remarkable 

 features. The corals which it contains have been 



* "Travels in North Aiperica," second series. 



