472 Notices of Memoirs — G. Linchtrom, Silurian Corals, etc. 



from west to east throughout the whole of this period. We find 

 tliat its delta advanced and receded with the depressions and eleva- 

 tions which led to the formation of this part of the Eocene. 



The Bracklesham Beds are the deposits of an almost tropical sea, 

 which extended south over France, but is not traceable north of the 

 Thames. The depression seems to have travelled from south to 

 north-east and caused the outfall of the Eocene river to shift towards 

 Hampshire. The Barton Beds show an influx of the northern sea 

 into the Bracklesham Sea, resulting in the migration of all the most 

 tropical forms — so that the dividing isthmus which previously 

 existed must have been broken through. The position of the river 

 was scarcely changed and the land fauna and flora remained tropical 

 until the close of the Headou period. Upheaval having caused the 

 recession of the Barton Sea. the southern sea again appeared in the 

 Brockenhurst Beds of the Middle Headon. The changes of level 

 during the Oligocene in England are similar, but affected smaller 

 areas, and were accomplished in a gradually diminishing temperature. 



I have touched very briefly on the physical conditions which pre- 

 vailed during the Eocene period, as my views on this part of the 

 subject have been already published. These conditions can, however, 

 be traced with great minuteness and comparative certainty. 



I. 1. SiLURISCHE KoKALLEN AUS NoRD EuSSLAND XTND SiBIEIEN ; 



VERZEicHNET VON G. LiNDSTROM. Bihang till K. Svenska Vet. 

 Akad. HandJingar, Band 6, No. 18. — Silurian Corals from North 

 Eussia and Siberia, described by G. Ltndstrom. Supplement 

 to the Transactions of the Eoyal Swedish Academy of Science, 

 Stockholm, 1882. 8vo. pp. 23, with a Plate. 



2. AnTEOKNINGAR OM SiLURLAGREN pa CarLSOARNE. Af G. LiNDSTROM. 



Ofver. Af. Kongl. Vet. Akad. Forhandlingar, 1882, No. 3.— 

 Notes on the Silurian Strata of the Carls Islands. By G. 

 LiNDSTROM. Proceedings of the Eoyal Swedish Academy of 

 Science. 8vo. pp. 30, with a Plate and Five Woodcuts. 

 N the first of these papers Prof. Lindstrom describes 27 species 

 and varieties of corals, which have been collected from Silurian 

 strata in four different and widely separated localities in Northern 

 Eussia and Siberia. Most of the forms belong to the familiar 

 Silurian genera Favosttes, HelioUies, Ealysites, etc. ; but in addition 

 to these, there are no fewer than three new genera, which have been 

 named Bhaphidophyllum, Gijrtophyllum, and Palcearea ; this last is 

 remarkable from the similarity of its structure, in many important 

 respects, to that of the Tertiary genus Litharea. From a table 

 appended it appears that 17 of these Siberian species occur also in 

 Sweden ; 12 in the English Silurian, and 8 in North America (in- 

 cluding Ealysites catenulariiis, L., and H. escJiaroides, Lam., which 

 are omitted from the list of American species, though of common 

 occurrence in that country). It is curious to note that two distinc- 



