REPORT OF THE STATE PALEONTOLOGIST 1901 563 



Tullberg 1 divides F, his Understa etagen, into 



a Zone with Phyllograptus sp. 



b Orthoceras limestone 



c Tetragraptus shales (lower Graptolite shales) 



d Ceratopyge limestone 



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

 Levis zone of Gurley, is liomotaxial with Tullberg's zone of the 

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

 zone with Phyllograptus sp., is also represented in the 

 Deep kill section. 



In the region of Christiania in Norway 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. p. 

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

 Ceratopyge limestone (3a y) and the Megalaspis limestone 



(3C a). 



Holm 2 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 investi- 

 gations regarding the morphology of these graptolites. 



In France the following species, originally described from the 

 Levis beds, Didymograptus pennatulus, D. 

 nitidus, D. bifidus, D. indentus, Tetragrap- 

 tus serra and T. quadribrachiatus, have been re- 

 ported by Barrois 3 from the graptolite schists of Boutoury 

 near Cabrieres in the Languedoc. He correlates this schist 

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

 of Canada and etage D d 1 /Jof Bohemia. 



In the succeeding year the same distinguished author an- 

 nounced the discovery of the species described by Hall as 

 Graptolithus richardsoni at La Mouchasse du 



x Skanes Graptoliter I, in Sveriges G-eologiska Undersokn. 1882. ser. G, 

 no. 50. 

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

 3 Annales de la Societe Geologique du Nord. 1892. t. 20, p. 75 ff. 



