Geol.-Vol. I.] SMITH— COMPARATIVE STRATIGRAPHY. 331 



The descriptions of the cephalopods of the Upper Trias 

 of the Oriental region have been pubHshed by E. von 

 Mojsisovics (24) in monographic form in the Memoirs of 

 the Vienna Academy of Sciences, and this work has since 

 then been translated into English and republished in the 

 Memoirs of the Geological Survey of India. 



In addition to the previously mentioned characteristics 

 of the Oriental region, it may be noted that Himgarites and 

 Ptychites occur well up in the Upper Trias, while in the 

 Mediterranean region Ptychites does not occur after the 

 Muschelkalk, and Hungarites has never been found above 

 the Longobardic stage, zone of Proti'achyceras archelaus^ 

 the base of the Upper Trias. 



The Arctic-Pacific Region. Triassic deposits are known 

 in the Arctic-Pacific region in Spitzbergen, in northern 

 Siberia near the mouth of the Olenek River, in eastern 

 Siberia near Vladivostok, in Japan, near Tonquin in 

 southern China, and on the islands of New Caledonia, 

 Rotti in the Indian Archipelago, and New Zealand. In all 

 probability this is not one faunal region, but is made up of 

 many heterogeneous provinces; but at present our knowl- 

 edge of the various faunas, except those of the Ussuri and 

 the Olenek provinces, is too meager to enable any geo- 

 graphic separation. Mojsisovics has included in this region 

 the Triassic deposits of western America; but further 

 investigation has shown that the relations of the faunas of 

 Idaho, California, Nevada, and British Columbia to those 

 of Asia are not sufficiently intimate to justify a union in one 

 geographic faunal region, at least for more than short 

 epochs. 



Lower Triassic faunas are known in the Arctic-Pacific 

 region only from Ussuri Bay in eastern Siberia, and from 

 near the mouth of the Olenek River in northern Siberia. 

 The Olenek province is characterized by the abundance of 

 Dinarites of the group of D. spiniplicati, Sibirites, and 

 Ceratites of the group of C . subrobusti. Ceratites siibro- 

 bustus Mojsisovics and Hedenstroemia mojsisovicsi Diener 

 are common to these beds and the Subrobtistiis beds of the 

 Oriental region, and serve as criteria in correlation. 



