: .\\ k ^EOCK-METAMOEPHISM. 



on the sliore at Sunderland which came under my notice have 

 their surfaces distinctly rippled j but they contain no fossils of 

 the kind merely bivalves (Schizodus &c.) . These beds,, however, 

 do not belong to the deep-water stage; for they overlie the 

 limestone (fossiliferous par excellence) which crops out at Hum- 

 bleton and other inland localities. Other beds occurring in 

 Lancashire, Yorkshire, and Cumberland, which possess similar 

 palseontological characteristics, are referable to the same 

 stage. 



Another fact of importance, which also seems to have been 

 overlooked by Dr. Ramsay, is that the Permian invertebrates, 

 which he assumes to have lived in " brackish water " of an 

 " inland unhealthy nature," are, as a rule, well-developed 

 species, and bear the stamp of having inhabited an open sea. 

 How can it be conceived that palliobranchs, only known as 

 denizens of the sea, could exist in brackish-water lakes ? 



As to why an exuberant variety of invertebrate marine life is 

 not a characteristic of the Permians, it must be borne in mind 

 that information on the distribution of these rocks is still very 

 limited. In the face of certain deposits in North America and 

 Central Asia, doubtfully referred to the Carboniferous, or 

 Permian Triassic system, it seems preferable to wait until they 

 have received fuller attention. In the Austrian Alps and in 

 Northern India there occur fossils (Ammonitida, Goniatidae, 

 &c.) of types indicating that the rocks containing them may be 

 of Permian age. 



Now, as my theory of regional cyclical vertical movements 

 admits of different conditions prevailing at the same time in 

 separated regions, it is not at all improbable that the marine 

 formations referred to may belong to the pelagic stage, and 

 nevertheless be synchronous with those which in Western Europe 

 gave birth to the shallow- water and estuarine (2nd or 4th) de- 

 posits of the Permian system. I would suggest the application 

 of this argument by way of explaining the difference between 

 the rock-systems of Europe and their presumed equivalents in 

 extra-European regions. 



Dr. Ramsay has introduced into his remarks on the Physical 

 Geography of the Permian Period * another matter, which he 



* Op. cit. pp, 149, 150. 



