Mevieivs — H. B. Woodward's Geology of England and Wales. 315 



This is a book without chapters. The Introduction contains a few 

 pages explanatory of the principles of geology, with a brief history 

 of English geologic research. Tliere is a very neat section across 

 England and Wales about the parallel of Lincoln, which shows the 

 outcrop of the Coal-measures in three distinct Coal-fields, together 

 with their relations to the Lower Palfeozoics of Wales and to the 

 Lower Carboniferous of the Pennine anticlinal. 



Part I. is devoted to the Paleozoic, which is made to include the 

 Archaean, the term now adopted instead of the Lewisian, or Laurentian, 

 of the previous edition. So much has been done during the last ten 

 years below the region of ascertained life that this poi'tion of the 

 second edition is altogether new. "The determination of the 

 ArcliEean rocks in England and Wales is mainly due to the researches 

 of Dr. H. Hicks, Prof. T. McK. Hughes, Dr. C. Callaway, and Prof. 

 T. G. Bonney." As some portions of the evidence have been con- 

 troverted by Dr. A. Geikie, the author proceeds to point out the 

 differences of opinion which have been expressed on this most 

 disputed subject, more especially in Pembrokeshire. " These differences 

 in the interpretation of this ancient ' Geological Eecord ' are serious, 

 but perhaps not quite so serious as they at first appear. It is admitted 

 that the rocks termed Pebidian underlie the oldest fossiliferous 

 Cambrian strata, and rest on the rocks termed Arvonian. The rela- 

 tive position and origin of the Dimetian granitoid rock are the main 

 points in question. It may be mentioned, however, that in other 

 areas, where Archaean rocks have been identified, two main divisions 

 are recognized, one of coarsely crystalline rocks (Dimetian), and the 

 other of eruptive rocks (Pebidian)." 



The readers of the first edition of Mr. Woodward's Geology of 

 England and Wales will bear in mind that he fully identified himself 

 with the Sedgwickian view of the classification of the Lower Paleo- 

 zoic rocks. Hence, for him, the Cambrian system includes every- 

 thing to the very top of the Bala beds. According to this arrangement 

 his Middle Cambrian consists of the Tremadoc Slates and Lingula 

 Flags : and further on he says, " The Middle Cambrian rocks introduce 

 many forms of Graptolites." This is not exactly the case. The 

 point perhaps is not one of much importance; but when we bear in 

 mind the great change in life-forms which occurs between the 

 Tremadoc series and the Arenig series, we must confess that the 

 Sedgwickian is apt to minimize this biological hiatus, just as the 

 opposite side desires to minimize the local unconformity in connection 

 with the Llandovery series. 



The correlation of the Lake-district rocks with those of Wales is very 

 fully treated. We miss the section by Harkness at the foot of the Cross 

 Fell range ; but on the other hand there is an interesting generalized 

 section across the Lake-district by Goodchild. Speaking generally, 

 however, the junction line of the Skiddaws and the Volcanics 

 should be somewhat more excavated than is there represented. 



The Old Red Sandstone and Devonian, and the question of their 

 relations to each other, are ably treated by the author, whose personal 

 experience in surveying some of these districts lends additional 



