﻿256 DR. A. VATJOHAN ON THE FAL^ONTOLOOICAL [May 1905, 



A. Legende de la Carte Geologique de la Belgique, 1900. 



In the short account of the Carboniferous Limestone given in this 

 pamphlet, the brachiopods mentioned are all long-range forms ; it 

 is, therefore, impossible, without a knowledge of the associated 

 fauna, to correlate the different stages with any great degree of 

 accuracy. 



T r Fauna cited: Spirifer glaber, Sp. tomacensis, and Spiriferina 

 octoplicata. 



Correlation: K, and probably Z r 



Reasons: Spirifer tomacensis belongs to the same species- 

 group as Sp. aff. clathratus, which occurs in K T , becomes 

 common in K 2 , and reaches its maximum in Z . Spiri- 

 ferina octoplicata is rare in K 1? characteristic of K 2 , and 

 extends to Z r Spirifer glaber I do not know with cer- 

 tainty in the Bristol area. 



T 2 . Fauna cited: Spirifer Koninchi (Sp. ductus) . Palechinids 

 at the top. 



Correlation : Z 2 . 



Reasons : Spirifer Konincki is a member of the same species- 

 group as Sp. tomacensis ; it occurs in Z , is probably com- 

 monest in Z c , and ranges on to y. A specimen of Palecliinus 

 was found by Mr. W. H. Wickes at the top of Z.,. 1 



Y ± . Fauna cited: Chonetes papilionacea. 

 Correlation : C. 



[Note. — In my system C forms the top of the Tournaisian, and not 

 the base of the Visean.] 



Reason : Presuming that giganteid Producti are rare or 

 absent, Chonetes papilionacea is only abundant in and just 

 above y, that is, in C. 



V 2 . Fauna cited : Productus Cora and Pr. giganteus. 

 Correlation: S 2 and D. 



Reasons: Productus Cora is most abundant in S 2 ; Pr. gi- 

 ganteus ranges from the upper part of S 2 through D. 



B. The Works of Mourlon 2 and Dewalque. 3 



I give my correlation without remark ; the reasons will be 

 apparent from my faunal tables. 



Assise I. Spiriferina octoplicata towards the bottom; Spirifer 

 tomacensis at the top. 

 Correlation: K and Z r 



1 See above, p. 238, footnote. 



2 ' Geologie de la Belgique ' vols, i & ii (1880-81). 



3 ' Prodrome d'une Description geologique de la Belgiqne ' 2nd ed. (1880) 

 chap. vi. 



