The marine Carboniferous of North-east Greenl. and its Brachiopod Fauna. 611 



d e p О s i t s , О r t О the divisions which, in Russia, are termed: 

 the Omphalotrochiis horizon, the Cora horizon and the Schwa- 

 gerina horizon. 



When we thus give a general determination of the age of 

 these formations, the question presents itself, whether a more exact 

 division of the measures can be carried out based on the age 

 of the brachiopod fauna. Here, of course, we again meet with 

 the difficulty that the greater part of the collections was obtained 

 from free-lying boulders, and that it was but rarely that several 

 species were found together so as to entitle us to say that they lived 

 together. We have given these instances above, and shall now pro- 

 ceed to make a further investigation of the vertical distribution of 

 these species thus occurring here in сотрапз\ 



Of the 8 species belonging to the Lower group, there occur in 

 the bituminous marl-shale 4 together; of these, Spirifer supramos- 

 quensis is characteristic for the middle Upper Carboniferous beds, 

 but ascends to a higher level, while, of the other species, Productus 

 simensis and Spirifer rectangulus are found in the Schwagerina lime- 

 stone, and Chonetella nasiita is described from the Productus lime- 

 stone in the Salt Range. An attempt to compare this special assemb- 

 lage of fossils with the Omphalotrochus horizon, can, consequently, 

 hardly be called satisfactory. 



Considerably better, however, will be the result of an examina- 

 tion of those fossils from the Upper group that occur together. In 

 the limestone boulder, N:o 154, from the Mallemukfjæld, there occur 

 8 species of the 17 belonging to the group: In addition to the ubi- 

 quitous Athyris Royssii and Reticularia lineata, there are also dis- 

 covered here the Upper Carboniferous Camarophoria cfr. Karpinskii, 

 and, of species that ascend from the measures just mentioned to the 

 Permo-Carboniferous, Rhynchopora Nikitini, Productus cancriniforinis 

 and tinianicus, and Pr. compressas from the Productus limestone of 

 the Salt Range, and last Strophalosia sp. indet. N:o 2. This associa- 

 tion of species contains, it is true, relatively many forms that ascend 

 into the younger Permo-Carboniferous deposits and into the Permian, 

 but a careful examination shows, however, thai it is just in the 

 Schwagerina horizon that such an assemblage is found. Another, quite 

 similar, but considerably poorer, embracing no more than 3 species, 

 occurs in the boulder N.o 197 from Ihe Eskimo Naze, where Pro- 

 ductus boliviensis and timanicus, which, from the Upper Carbonife- 

 rous measures ascend into the Permo-Carboniferous, occur together 

 with Pr. pseudohorridus from the Spitzbergen Spirifer limestone and 

 Productus flint. These fossils point very decidedly to the Schwage- 

 rina horizon, and from them it would be difficult to discover any 



