474 
THE GEOLOGIST. 
Plesiosauri spitting fire, Iguanodons with hook-noses, Pterodactyles which 
look wondroiisly like storks, and Hawaiian volcanos bubbling away merrily 
at the risk of engulfing the fossil scorpions at their brink. We hope that 
our German palaeontologists really do not seriously promulgate this work 
in the hope of its difi'using elementary instruction amongst the masses of 
that profound-thinking nation. 
TJeher Placodus gig as, Agassiz, und Placodiis Andriani. By Dr. Carl 
Friedrich Wilhelm Braun. 4to. Miiuster : Bayreuth. 1862. 
The work before us contains a detailed monograph of this most inter- 
esting genus, which was demonstrated by Owen, in the year 1858, to be a 
reptile, and removed from the class of fishes with which it had been classi- 
fied by Agassiz. The most interesting and novel part of the work is the 
following statement : — 
" We find in the musclielkalk of the hill at Leineck peculiar flat, broad, 
polymorphic, small or large masses, sometimes a foot in length. They are 
composed of bluish-grey flint, in which are embedded numerous small 
particles of a darker colour, composed of the fossilized debris of shells, 
not larger than one line each. Examined microscopically, we detect a 
structure which leaves no doubt that they are the fragments of rather 
small and very convex shells. Sometimes we can also distinguish single 
teeth and scales of fishes of the same formation, namely, Psammodus, 
Hyhodus, and Acrodus. We cannot doubt that these siliceous masses are 
coprolites, which must belong to Placodus, for no other isaurian or fish of 
those triassic strata has been provided with a dentition adapted to crush 
hard shells, like those of Terehratula. The Placodus fed on hard-shelled 
mollusca, and occasionally on fish. It is interesting to compare Owen's 
views on the nature of the food of those animals with our account, and to 
see how views gained from very opposite points of examination may per- 
fectly agree in the final result. K.. Owen, guided by the arrangement 
and the structure of the teeth, gives us the following ingenious explana- 
tion." 
Then follows the well-known passage from Prof. Owen's memoir, read 
before the Royal Society, the accuracy of which induction is corroborated 
by the German palaeontologist. 
Aj)ergu Geologiqne du Departement de la Moselle. Par C. Fridrici, Pro- 
fesseur aux Ecoles Municipales de Metz. Leipzig : J. Rothschild. 
1862. 
An unpretentious little book, in a paper cover, illustrated with woodcuts 
of the most ordinary character, and creditable only, as engravings, to an 
engraver's youngest apprentice. But we do not mean to laugh at them 
either, although one of them is printed upside down ; anybody can see that, 
because houses do not adhere to roofs of caverns, but point their chimneys 
upwards in the air. " In producing this book," says the author, " we do 
not pretend to offer a complete study of the geology of our department ; 
it is simply a resume made in the hope of its being useful to those of our 
pupils who, after having followed our lessons, would wish to make in our 
country application of that which they have learnt." Indeed, Monsieur 
Fridrici, we have a respect for your humble little hrochure, and if English 
schoolmasters would do as much, and as well, for their pupils as you have 
done for j^ours, we should have more and better young geologists than we 
have. Sincerely we echo your wish, that your efforts may bring forth the 
fruits you desire. 
