20 SCIENCE PROGRESS. 



representatives of the now well-known Permo-Carboniferous 

 limestones, developed in India and elsewhere. We have 

 therefore in Spitzbergen : — 



1. Hekla Hook Beds = Silurian. 



2. Liefde Bay Beds = Devonian. 



3. Ursa-stage = Passage between Devonian and Car- 



boniferous. 



4. Coal-bearing Strata = Lower Carboniferous. 



5. Limestones = Permo-Carboniferous. 



The mountain limestone proper, which should occur 

 between 4 and 5, has not been detected, but it is suggested 

 that it is possibly represented by the Cyathophyllum lime- 

 stone. 



The Marine Upper Carboniferous beds of Arkansas are 

 the subject of a paper by J. P. Smith (26). He states that 

 they correspond to the lower part of the Cisco beds of 

 Texas, and belong to the top of the true Carboniferous, 

 and are below the transitional Permo-Carboniferous. He 

 remarks that Waagen's comparative table showing the 

 relationship of the Upper Palaeozoic strata all over the 

 world is not generally accepted by most American geolo- 

 gists as regards the position assigned to some American 

 deposits. Whilst this paper shows the gradual acceptance 

 of the existence of marine coal measures and Permo-Car- 

 boniferous faunas (with which we in Britain are practically 

 unacquainted), certain apparent abnormalities are touched 

 on, and the author remarks that they have been explained 

 by some writers as explicable upon the theory of Colonies. 

 This explanation he seems to look upon with approval. 

 The difficulties will no doubt be cleared up ultimately, and, 

 perhaps, when that is done, Waagen's correlations will be 

 proved to hold good for America also. 



No important papers have been published concerning 

 the Permian rocks proper during the six months under 

 review. 



BIBLIOGRAPHY. 



(1) DAWSON, Sir W. The Fossil Plants of Canada as Tests of 

 Climate and Age. Natural Science, vol. iv., p. 177. London. 



