t-"> s Sri, nt hie Intelligence. 



Beekmantown, for the latter series has but few of these shells, 

 whereas there is an abundance in the former and its equivalent, 

 the Stones River series. On the other hand, the Ceratopyge 

 formations of Sweden, which are absent in Esthonia, are unmis- 

 takably of Beekmantown age. The Normanskill Raymond 

 regards as probably of upper Chazy time. 



Twenhofel reports on the higher Ordovician and the Silurian, 

 and as these deposits have many fossils in common with those of 

 America, and more especially those of Anticosti, he has far less 

 difficulty than his colleague in determining the equivalent forma- 

 tions. The lower Lyckholm Bassler regarded as intimately con- 

 nected faunally with the middle Ordovician, a correlation accepted 

 by none, and now Twenhofel shows that the Lyckholm is hot 

 divisible, but that the whole of it is upper Ordovician in age and 

 about equivalent to the middle Richmondian. The following 

 Borkholm is still higher Richmondian and correlates with the 

 Ellis Bay horizon of Anticosti ; both are referred to the Ordovi- 

 cian period. Then followed emergence of the region and Estho- 

 nia was not again invaded by the sea until long after the Silurian 

 had begun, in about Clinton time. 



The Silurian of Esthonia and that of Gotland are very different 

 in their faunal make-up and in the nature of the sediments as 

 well. The difference is apparent]}' wholly due to the fact that 

 the Gotland sea abounded in coral reefs, and as these grew far 

 more quickly than the surroundiug sediments accumulated, and 

 show, consequently, a greater variation in strata, this led to 

 the development of many different faunules, of slightly different 

 geologic ages, which are now found in the same stratigraphic 

 horizon. This condition has long perplexed stratigraphers, but 

 Twenhofel now shows from a study of recent coral reefs how the 

 Gotland stratigraphy may be harmonized with that of other 

 Silurian areas. It is interesting reading, and his conclusions are 

 all the more acceptable because he has unravelled a similar con- 

 dition in the Silurian of Anticosti. 



The authors are to be congratulated upon the great amount of 

 first-hand information here presented, and their work clarifies and 

 greatly advances our knowledge of the faunal interrelations of 

 the European and American Ordovician and Silurian systems. 



c. s. 



2. Upper Ordovician formations in Ontario and Quebec; 

 by A. F. Foeeste. Geol. Survey Canada, Mem. 83, 1916, pp. 

 iii, 279, 8 figs. — This memoir describes in detail the stratigraphic 

 and faunal succession of the Cincinnatian series east of Montreal 

 and Ottawa, Canada, west of the Adirondacks of New York, 

 and in the Lake Huron region. All of the species identified by 

 the author have been arranged in tabular form, so as to show 

 their stratigraphic range, by Miss A. E. Wilson. c. s. 



3. The Lower Eocene floras of Southeastern North America ; 

 by Edward Wii.ber Berrv. U. S. Geol. Survey, Prof. Paper 

 91, 1916, 481 pp., 117 pis., 16 text figs. — In this great monograph 



