84 Revieivs — Symonds' Records of the Rocks. 



and Cambro-Silurian series. The history and description of the 

 Llanberris, Longmynd, and Harlech rocks, which, with the Mene- 

 vian group, constitute the lower division of the Cambrian series, is 

 written as those only can who have themselves examined the area 

 they occupy. Snatches of history, antiquity, archaeology, natural 

 history, and scenery, are so judiciously interwoven with the petro- 

 logical descriptions and geological aspects of the Cambrian rocks, 

 that one is almost tempted to journey, book in hand as our guide, 

 to explore and examine these mysterious monuments of high 

 antiquity, wherein are entombed the very earliest forms of existence 

 known upon the globe. He who has never seen the Longmynds, 

 the rocks of Harlech, the schists and slate of Barmouth, and Llan- 

 berris, with Bardsey and St. David's Head, can little comprehend 

 the early history of the British islands, either physically or paleeon- 

 tologically. It is a feature in the " Eecords of the Eocks " to create 

 that desire, and with the "Records" in hand, and the maps prepared 

 by the Geological Survey, little else is needed, save note-book and 

 hammer, to enable the student or tourist to read the far past clearly 

 and unmistakably. The author neglects not to associate with the 

 rocks the localities of many of the rare Scandinavian plants ; the 

 home of the wild bird ; the brooks and tarns, with their rare fish ; 

 and carefully he notices and names the fossil fauna in those districts 

 where, without almost direct guidance, the metamorphosed character 

 of the rocks would defy their detection. The seventy-seven pages 

 devoted to the Laurentian and Cambrian rocks and their associated 

 history is the best digest in our language, and is written by one who 

 has a great knowledge and love of nature, and whose life has been 

 devoted to Cambrian and Silurian geology, and the natural history of 

 the area embraced by the " Eecords." 



Chapters iv., v., and vi., comprising 134 pages, are devoted to the 

 Silurian System, or to the Lower, Middle, and Upper Silurian rocks. 

 Mr. Symonds places the Lower Llandeilo (Arenig or Skiddaw rocks 

 of Sedgwick) at the base of the Silurian; the Geological Survey 

 make the Lingula flags their base. It is a pity so many " tops and 

 bottoms " are made to these lower rocks. These di^^erse views have 

 led to much confusion. It is well, howcA^er, that we have a published 

 line, so that in the field at least the horizon is established, modify 

 it how we may in the study. Controversy, however, concerns 

 us not here ; neither do the minor differences of authors enter into 

 notice of the " Eecords." All agree in one thing — that the chaos of 

 the older writers, the " Grauwackians," was reduced to systematic 

 order by Murchison, Sedgwick, and Lewis. To the former, however, 

 must be awarded the high credit of definitely determining and 

 defining the " Silurian system." Few even now realize that great 

 and difficult work. The author of the "Eecords of the Eocks" is 

 one, however, who has spent his days upon the earliest life rocks 

 that lifted their heads to the sun — the oldest rock masses in the 

 world's history. He has been a Silurian student from boyhood. 

 His analysis of Lower Palseozoic time tells us that he has studied 

 well and diligently, and has mastered and comprehended the scope 



