40 G. Schuchert — Russian Carboniferous and Permian. 



" Tschernyschew a]so correlates the Russian section with 

 that of the Mississippi Valley. His correlation may be correct, 

 but the Pennsylvanian faunas of the latter area are so widely 

 different from those of our Western States which the Russian 

 ones most closely resemble, that, in the opinion of one who has 

 had some acquaintance with both types, a precise correlation 

 is, in our present knowledge, impossible. The beds placed in 

 alignment by Tschernyschew contain faunas so widely dissimi- 

 lar that it seems an act of temerity to group them together. 

 The evidence for so doing consists in part of the occurrence of 

 certain American species in the Russian faunas, but the identi- 

 fications, if one may judge by the figures given, in some cases 

 are questionable and in others consist of such long-ranged 

 types that in view of the really small percentage which these 

 forms bear to the entire fauna, the evidence appears of dimin- 

 ishing significance the more critically it is examined " (3, p. 

 24). 



Part II. The Work of Noetling. 



1. Ueber das Verhaltniss zwischen Productuskalk und Ceratitenschichten 

 in der Saltrange, Indien. Von Fritz Noetling. Centralblatt fur Min., 

 Geol. und Pal., 1904, pp. 321-327. 



2. Ueber Me dlicottia Waag. und Episageceras n. g.. etc. Yon Fritz Noet- 

 ling. Neues Jahrb., Beil.-Band XIX, 1904, pp. 334-376. 



3. Ueber das Alter der Otoceras-Schichten von Rimkin Paiar (Painkhanda) 

 in Himalaya. Von Fritz Noetling. Neues Jahrb. , Beil.-Band XVIII, 1904, 

 pp. 528-555. 



The first of these papers is a short summary of an earlier, 

 very important and extensive discussion by the same author (4. 

 Beitr'dge zur Geologie der Salt Range, etc., Neues Jahrb., 

 Beil.-Band XIY, 1901, pp. 369-471), describing the sequence 

 of the horizons closing the Paleozoic and their unbroken suc- 

 cession into the well-developed Lower Triassic of India. Noet- 

 ling's work has been assailed by one of the foremost geologists 

 of Europe, and as the proper correlation of the Productus-lime- 

 stone with European horizons affects the various formations 

 composing the Permian system, it is well for Americans to 

 become acquainted with these latest works, especially since 

 Asiatic faunas are now known in southwestern Texas, Cali- 

 fornia, and Alaska. 



Noetling states : " Upon the Cambrian beds of the Salt 

 Kange there lies discordantly a sedimentary complex, followed 

 by a series that Koken has established as of Jurassic age, in 

 which there is no evidence of discontinuity, although during 

 its deposition at various times very different physical conditions 

 must have occurred. 



" On the basis of origin, one can separate this sedimentary 

 complex into three divisions of varying thickness, namely : 



