REPORT OF THE STATE PALEONTOLOGIST 1901 563 



Tullbergi divides F, his Understa etagen, into 



a Zone with Phyllograptussp. 



& Orthoceras limestone 



c Tetragraptus shales (lower Graptolite shales) 



d Ceratopjge limestone 



The Tetragraptus zone of the Deep kill section or the Main Point 

 Levis zone of Gurley, is Jiomotaxial icith Tullherg's zone of the 

 Tetragraptus shales. As we shall see presently his zone a, the 

 zone icith P h y I I o g r a p t u s sp., is also represented in the 

 Deep kill section. 



In the region of Christiania in Noricai/ the presence of the 

 fauna of the Tetragraptus zone has been demonstrated by 

 Kjerulf (his " lower Graptolite shales ") and Brogger (" Phyllo- 

 graptus shales/' in Die silurischen Etagen 2 and 3, etc. 1882. j). 

 18 ff). They found this Phyllograptus shale (3b) between the 

 Ceratopyge limestone (3a f) and the Megalaspis limestone 

 (3c a). 



Holm^ obtained species of the Tetragraptus zone, such as 

 T. bigsbyi and Phyllograptus angustifolius 

 from glauconitic gray Orthoceras limestone (Planilimbata lime- 

 stone) of Oeland and partly based on these his beautiful iuA^esti- 

 gations regarding the morphology of these graptolites. 



In F'^ance the following species, originally described from the 

 Levis beds, Didymograptus pennatulus, D. 

 nitidus, D. bifidus, D. in dent us, Tetragrap- 

 tus serra and T. quadribrachiatus, have been re- 

 ported by Barrois^ from the graptolite schists of Boutoury 

 near Cabri^res in the Languedoc. He correlates this schist 

 with the middle Arenig (Skiddaw) of England, the Quebec beds 

 of Canada and etage D d 1 ;5of Bohemia. 



In the succeeding year the same distinguished author an- 

 nounced the discovery of the species described by Hall as 

 G r a p t o 1 i t h u s r i c h a r d s o n i at La Mouchasse du 



^Skanes Graptoliter I, in Sveriges Geologiska Undersokn. 1882. ser. C, 

 no. 50. 

 ^Sveriges Geologiska Undersokn. 1895. ser. C, no. 150. 

 ^\nnales de la Societe Geologique dn Nord. 1892. t. 20, p. 75 ff. 



