5l8 JAMES PERRIN SMITH 



them. But before this, in 1863, de Koninck, who also described a 

 number of ammonites from the Ceratite formation, referred them 

 very doubtfully to the Paleozoic, because they were supposed to 

 have come from the Productus limestone. C. L. Griesbach^ who 

 first described the fauna of the Otoceras beds of India, referred 

 them to the Lower Trias, in which he has been followed by 

 Wilhelm Waagen^ and Carl Diener.3 These writers consider the 

 lower part of the Ceratite formation to be younger than any 

 known Permian, and older than any fauna described from the 

 European Trias, but they regard the affinities of the species as 

 closer to known Mesozoic types, and the beds were considered 

 as homotaxial with the lower part of the Werfen sandstone, the 

 base of the Trias in the Mediterranean region. Now since this 

 part of the Mediterranean section is barren of fossils, this corre- 

 lation is based entirely on the stratigraphic position of the 

 Ceratite formation. 



C. Diener'*, in describing the fauna of the Proptydiites beds 

 of Ussuri Bay in eastern Siberia, correlated them with the Otoceras 

 beds of India, because of the occurrence of several species com- 

 mon to the two reof-ions. It is, therefore, evident that while the 

 correlation of the Ceratite formation of India with the Proptydiites 

 beds of Siberia and the Meekoceras beds of western America may 

 be accepted as correct, the final determination of the age of these 

 beds depends entirely on a comparison with the type of the 

 Lower Trias, the Buntsandstone of Germany, and the Werfen 

 beds of the Alps. 



In spite of the weakness of this argument, the Ceratite forma- 

 tion of India has until recently gone unquestioned as the type 

 of the strictly marine equivalent of the Lower Trias, and all 



'Records Geol. Siirv. of India, Vol XIII, 1880. Paleontological Notes on 

 the Lower Trias of the Himalayas, p. 94. 



^'Mem. Geol. Surv. India, Pal. Indica, Ser. XIII. Salt Range Fossils, Vol. II. 

 Fossils from the Ceratite Formation. 



'i Ibid., Ser. XV. Himalayan Fossils, Vol. II, Part I. Cephalopoda of the 

 Lo\ver Trias. 



■♦Mem. Com. Geol. St. Petersbourg, Vol. XIV, No. 3. Triadische Cephalopoden- 

 faunen der Ostsiberischen Kiistenprovinz. 



