PALEOZOIC AND MESOZOIC BORDER-LINE 519 



correlations of the marine beds have been made by comparison 

 with it. During the last year F. Noetling/ paleontologist of the 

 Geological Survey of India, has startled geologists in their fancied 

 security, by the statement, based on his later investigations, that 

 the Otoceras beds of India belong to the upper Permian, and are 

 older than the Werfen beds of the Alps. As they lie conform- 

 ably upon the upper Productus limestone, they represent, accord- 

 ing to Noetling, strata of which the equivalents are lacking in 

 the European section. Accordingly he proposes to call the 

 entire Ceratite formation upper Permian, and as a name for the 

 stage he proposes the term Bactrian. If this should prove to 

 be correct it would throw the Ceratite formation of India, the 

 Proptychites beds of Siberia, and the Meekoceras beds of Idaho 

 and California into the upper Permian. 



A. von Kraft, "" also of the Geological Survey of India, agrees 

 with Noetling, but only as to the Permian age of the Otoceras 

 beds ; the upper part of the series where Meekoceras and Flem- 

 ingites are so abundant he regards as certainly of lower Triassic 

 age. He says that Medlicottia dalailamae Diener of the Otoceras 

 beds is identical with M. wyymei Waagen of the upper Productus 

 limestone, and that Cyclolohis oldhami Waagen and Xenaspis 

 carbonaria Waagen, which in the Salt Range occur in the mid- 

 dle Productus limestone, in the Himalayas occur in the Ruling 

 Productus shales only twenty or thirty feet below the Otoceras 

 beds. This would make the bottom of the Otoceras beds (the 

 lower Ceratite limestone) the equivalent of the upper Productus 

 limestone of the Permian. This argument, however, might work 

 both ways, for it would just as well prove that the upper Pro- 

 ductus limestone belonged to the base of the Trias, since in any 

 case the division line must be arbitrary. Nor would the finding 

 of Productus itself in the Otoceras beds prove them to be 



'Geol. Surv. of India, General Rept. for 1899 (1900). Notes on the Relation- 

 ship between the Productus Limestone and the Ceratite Formation of the Salt Range, 

 and Neues Jahrbuch fiir Min. Geol. und Pal., 1900. Bd. I, p. 139, Ueber die Aufifin- 

 dung von Otoceras sp. in der Salt Range. 



^Centralblatt fiir Min. Geol. und Pal. Bd. II, 1901, p. 275, Ueber das Permische 

 Alter der Otoceras-Stufe des Himalyas. 



