224 INDEX TO THE STRATIGEAPHY OF NORTH AMERICA. 



The Bafiin Land fauna had an early introduction of Upper Silurian genera in the corals 

 Halysites, LyeHia, and Plasmopora. In Manitoba similar conditions occur in the presence of 

 Halysites, Favosites, and Diphyphyllum. Other Upper Silurian types do not appear to be 

 present. 



The Trenton fauna of Silliman's Fossil Mount, at the head of Frobisher Bay, has 72 species, 

 of which 28 are restricted to it. This fauna shows an intimate relationship with that of the 

 Galena of Minnesota, Iowa, and Wisconsin. Fifty-seven per cent of the species of Bafiin 

 Land also occur in the Galena of the regions just mentioned. 



S 27. EASTERN COAST OF GBEENLAND. 



The Ordovician and possibly Cambrian of northeastern Greenland are described 



by Nathorst,™^'' who says : 



East from the Archean follows a formation of sedimentary rocks which are without doubt 

 older than Devonian and at least in part must be considered of Silurian [Ordovician] age, since 

 there were found at Cape Weber, besides others, Orthoceratites, together with small Orthis or a 

 closely related brachiopod and small gastropods. Although these fossils in consequence of 

 pressure and the poor condition of preservation resulting therefrom can not be specifically 

 determined, a Silurian [Ordovician] age is nevertheless indicated, since the Orthoceratites are 

 younger than Cambrian; still it is not impossible that in the lower formations there may be 

 Cambrian strata. 



The strata of which the formation is composed are very variable and consist of white, 

 yellowish, gray, and black limestone or dolomite; red, green, chocolate-colored, and dark 

 slates; and red sandstone, together with perhaps in the lower portions yellowish sandstone. 



The Ordovician strata of this region are much folded and conformably overlain 

 by the Devonian. 



