Dr. J. H. Parkinson — The Culm in South Germany. 275 



The foregoing list contains no single species in common with the 

 ■CephalopodLimestoneofErdbach-Breitscheid/ universally recognised 

 as the lowest niveau of the Culm in South Germany. Only eight 

 of the enumerated fossils, moreover, have been found in the next 

 succeeding horizon, i.e. in the Posidonia Slates of Herborn and 

 Aprath (among them the English forms Chonetes Hardrensis, Zeptcena 

 rhomboidalis, Ortliotheihes crenistria, Orthis Michelini, and Pleura- 

 dictyum Dechenianum) , nor are the best known species of the Posidonia 

 Slates of Germany and of the Culm Measures of England found at 

 Konigsberg. We must conclude, therefore, that we have to do with 

 a new fauna of the Culm, so far as these localities are concerned. 



Crossing the Rhine, however, we meet with a remarkably 

 <3orresponding fauna in the Carboniferous Limestone of Belgium. 

 This limestone is now divided into three main horizons, those of 

 Etroeungt (transitional between the Upper Devonian and the 

 Carboniferous), Tournai, and Vise. Only eight Konigsberg forms 

 occur in the lowest, 12-13 in the central, but no less than 40 in the 

 uppermost of these ; in other words, 83 per cent, of the species 

 found at Konigsberg ai'e also met with in the Vise horizon of the 

 Carboniferous Limestone, amongst them many forms which are 

 in Belgium confined to this niveau, such, to name no others, as 

 Productus giganteus, P. plicatilts, P. ptmctatus, P. fimhriatus, Chonetes 

 papilionacea, and Griffitliides seminifer. We are consequently un- 

 doubtedly justified in regarding the slaty breccia of Konigsberg as 

 the equivalent of the Vise horizon of the Carboniferous Limestone. 

 This result affords us a means of zoning the Culm on the basis of 

 the division of the Lower Carboniferous in Belgium. In the 

 Rhine district two different Culm faunas have up to the present 

 been recognised, that of Erdbach-Breitscheid and that of Herborn, 

 Aprath, etc. The Cephalopod Limestone of Erdbach-Breitscheid 

 has been shown by Holzapfel to be the equivalent in age of the 

 Etroeungt beds in Belgium, identical or similar Prolecanites occurring 

 in both. Recently, too. Dr. Drevermann has described a similar 

 fauna from Ratingen, on the right side of the Rhine. The Mar wood 

 and Pilton beds of North Devonshire, which are of transitional 

 character, are possibly also of similar age. Since the Konigsberg 

 breccia must be regarded as the equivalent of the Vise horizon, 

 and at the same time lies stratigraphically higher than the Posidonia 

 Slates, the latter must be regarded as approximately corresponding 

 to the beds of Tournai, i.e. to the middle division of the Carboniferous 

 Limestone, and the same must also be true of the Posidonia Slates 

 of the English Culm Measures. We may summarize the results 

 arrived at in the following table : — 



Zones of the Culm ox the Eight Zones of the Carboniferous 

 Bank of the Rhine. Limestone of Belgium. 



3. Slates with the Konigsberg breccia. 3. Vise horizon. 



2. Posidonia Slates of Herborn, etc. 2. Tournai horizon. 



i. Limestone of Erdbach-Breitscheid and 1- Etroeungt horizon, 



basal ilinty slate. 



^ Cf. Holzapfel, " Die cephalopodenfiihrenden Kalke des unteren Carbon von 

 Breitscheid-Erdbach bei Herborn," Dames und Kayser, Palaont. Abt., Bd. v, 1889. 



