Reviews — Prof. Gossclcfs Cours Elementaire cle Geologie. 33 
Bostrichopus antiqaus, Goldf. The only known and wonderfully 
perfect example of which was found in the Posidonomya sckists or 
Culm near Herborn in Nassau, and is preserved in the Bonn 
Museum. 
Lying before us is another work of Professor Ferd. Eoemer’s, 1 
published several years ago, with all the advantages that can be de- 
rived from fine paper, good printing, and beautifully finished plates. 
It is a handsome quarto monograph of the Fossil Fauna of the 
Silurian Drift of Sadewitz in Lower Silesia. It would seem absurd 
to compare the eight splendid plates which illustrate it with those of 
the “ Lethma,” but an examination of both will show how thoroughly 
they are adapted to their respective objects, and if the latter appear 
rough and ready by the side of the foriner, they will lose none ot 
their value on that account. 
This Sadewitz Monograph is quite a palteontological and geolo- 
gical curiosity, being the description of a fauna from unknown 
beds, the fossils forming which were all collected from Drift 
deposits. Seventy-three species are enumerated, including twenty- 
five new ones, and a careful study of the group of organisms thus 
brought together, and of the lithological character of the original 
matrix still associated with the specimens, led the author to hazard 
the Suggestion that the Silurian rocks which once contained them 
are to be sought in the Eastern Russian provinces, either in 
Esthonia or still under the sea in the neighbourhood. 
Among the species figured some splendid sponges are very notice- 
able ; such as, Aulocopium diadema, Osw. ; A. aurantium, Osw. ; 
A. hemisphwricum, Roem. ; Astylospongia incisa, Roem., etc., etc. 
The position of the Lyckholm beds in Esthonia, which seem to be 
the most likely horizon whence these fossils were derived is towards 
the top of the Lower Silurian, between the Wesenberg beds (below) 
and the Borkholm beds. G. A. L. 
III. CODRS ELEMENTAIRE DE GEOLOGIE A l’üSAGE DE L’ENSEIGNE- 
MENT SECONDAIRE CLASSIQUE ET DK l’eNSEIGNEMENT SECONDAIRE 
special.” By Prof. J. Gosselet. (Paris, 1876.) 
T HIS little book of not quite 200 pages is expressly written for 
the tise of beginners, but self-teaching by its aid is not contem- 
plated, the knowledge which it imparts being intended to be supple- 
mented by the Professors in the French Ly cees. This the author 
explains in his Preface, in which he notes the difficulty (greater in 
France than in England) of giving public-scliool boys instruction in 
out-door geology. Fortunately for bis pupils, Prof. Gosselet is him- 
self an enthusiastic field geologist, and we are not surprised to see 
that he very justly compares the necessity for field-work in learning 
geology to that of laboratory-work as regards chemistry. 
In order to give learners an idea of succession in time, the writor 
compares the geological divisions to the reigns in which historical 
1 “ Die fossile Fauna der Silurisclien Diluvial-Gescliiebe von Sadewitz bei Oels 
in Nieder-Schlesien.” By Dr. Ferd. Roemer. 4to. Breslau, 1861. 
DECADE U. — VOL. IY. — NO. I. 
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