DEVONIAN AM' OI.H |;KD SANHSToNK sYSTK.M 



ami there is nothing analogous to the Gedinnian li.-li fauna of 

 Pteraspis and Cephalaspis, etc. ; consequently it is supposed that 

 the Lower Devonian has thinned out northwards from Bohemia 

 and eastwards from the Harz district against the shore of a northern 

 Devonian continent ; for though the Devonian is largely developed 

 in the Baltic provinces of Russia, it does not include any repre- 

 sentative of the Lower Series. 



Both Middle and Upper Devonian are well developed in Poland ; 

 the former by a series of marls and limestones with Calceola sandalina 

 and many of the typical Eifelian and Give"tian fossils, the latter by 

 limestone and shales in the following order: 



3. Clymeuia shales in three zones. 



2. Calcareous shales with Geph. intumescens. 



1. Kielce limestone with Rliynch. culoides. 



In the Baltic provinces (Livonia and Courland) a red sand- 

 stone with fish remains lies unconformably on both Silurian and 

 Ordovician, and is succeeded by dolornitic limestones with a marine 

 fauna. These limestones are divisible into four bands, the two 

 lower containing a local fauna of Spirifers and other Brachiopods ; 

 the third band, however, yields many characteristic Givetian species, 

 so that the lower are doubtless equivalent to the Eifelian, and the 

 highest bed is marked by the abundance of another species of 

 Spirifer (S. Anosoffi). 



Finally, there is a second set of sandstones taking the place of 

 the Upper Devonian, and comparable to the British Upper Old 

 Red Sandstone, for they contain Holoptychius and Asterolepit. 

 Eastward, however, in Central Russia they are replaced by red 

 marls and limestones with marine shells, and still farther east, on 

 the flanks of the Oural Mountains, we again find a complete marine 

 facies of the whole Devonian System. Apparently Novaya Zembla 

 was also covered by the Devonian Sea, for at Cape Grebein vertical 

 beds with Proetus are regarded as Lower Devonian, and are con- 

 formably succeeded by strata which have yielded Spirifer Anosoffi. 



II. THE OLD RED SANDSTONE FACIES 



As stated on p. 199 the marine Devonian facies does not occur 

 in Britain north of the Bristol Channel, its place in Wales, Scotland, 

 and the north of Ireland being taken by the great aeries of sand- 

 stones, marls, flagstones, and conglomerates, which are still known 

 by the cumbrous name of the Old Red Sandstone. 



Although this Old Red Sandstone is believed to be divisible into 



