﻿32 Revieivs — Prof. Ferd. JRoemer's Lethcea Palceozoica. 



The stratigraphical divisions in which the fossils I'epresented are 

 grouped are purposely the largest that could with propriety be 

 adopted. They are as follows : 1. Cambrian (pi. i., ii.). 2. Lower 

 Silurian (pi. iii.-viii.). 3. Upper Silurian (pi. ix.-xix.). 4. Lower 

 Devonian [Old Eed Sandstone] (pi. xx.-xxii.). 4a. The same 

 [Coblenz Grauwacke] (pi. xxiii.-xxv.). 5. Middle Devonian 

 [Eifler-Kalk] (pi. xxvi.-xxxi.). 5a. The same [Paifrather-Kalk] 

 (pi. xxii.). 6. Devonian, plants (pi. xxxiii., xxxiv.). 7. Upper 

 Devonian [Goniatite beds] (pi. xxxv.). 8. The same [Glymenia 

 beds] (pi. xxxvi.). 9. Culm (pi. xxxvii., xxxviii.). 10. Carboni- 

 ferous Limestone (pi. xxxix.-xlvi., xlviii.). 11. Coal-Measures 

 (pi. xlvii., il.-lv.). 12. Permian (pi. Ivi.-lxii.). 



Pre-Cambrian fossils do not find favour in the author's eyes, and 

 such things (perhaps this is the safest term !) as Eozoon and Palceo- 

 pyge are not depicted on his plates, although it is to be hoped that 

 they will not be as utterly ignored in the text. The term " Proto- 

 zoic," moreover, which Dr. Eoemer attaches to the first plates as 

 synonymous with Cambrian, probably further indicates his views as to 

 the geological evidences of the beginnings of life. The succeeding 

 horizons are very fully represented by figures of fossils from all 

 parts of the world, and of these many will be invaluable from the 

 fact that they are reproduced from works of very difficult access to 

 the majority of students, while others have been drawn from striking 

 specimens expressly for this publication. The plates are litho- 

 graphed in a bold clear style, quite suitable to the object of the 

 " Letheea " ; but there is considerable difference discernible in the 

 quality of their printing. Some few — such as pi. 39 for instance — 

 being decidedly inferior to the rest in this respect. 



Perhaps the most interesting group of organisms here depicted is 

 that of the Culm, both on account of the peculiar geological relations 

 of that great Continental series, and because the Bi"eslau Professor of 

 Geology is of all others, we may say, the one to whom the unra- 

 velling of these relations is chiefly due. It is with much interest that 

 we await the explanator^r matter to accompany these plates. We 

 may note even now, however, as a significant fact, that the Culm is 

 here made to come immediately after the Upper Devonian, witli this 

 observation in brackets, " Eigeuthiimliche den Kohlenkalk vertre- 

 tende sandig thonige Facies des unteren Kohlengebirges."^ The 

 Silesian Culm has so often been looked upon as the equivalent of the 

 Millstone Grit, or at least of the Upper Limestone Series or Yoredales, 

 that the view that it should be referred to an horizon considerably 

 lower in the Carboniferous Series will be new to many, although 

 recent researches have a strong tendency in that direction. 



It is a question whether absolutely unique specimens should find 

 a place among a collection of charactei'istic fossils such as these 

 plates profess to represent, yet we doubt whether any one will 

 quarrel with the selector when he discovers in plate 38 a copy of 

 Goldfuss's figures of that most curious and astonishing little animal 



1 A peculiar sandy-clay fades substituting the limestone of the Lower Coal 

 formation. 



