474 



THE GEOLOGIST. 



Plesiosauri spitting fire, Ignanodons with hook-noses, Pterodactyles which 

 look wondrously like storks, and Hawaiian voicanos bubbling away merrily 

 at the risk of engulfing the fossil scorpions at their brink. We hope that 

 our G-erman paleontologists really do not seriously promulgate this work 

 in the hope of its diff'using elementary instruction amongst the masses of 

 that profound-thinking nation. 



Ueher Placodus gigas, Agassiz, und Flacodus Andriani. By Dr. Carl 

 Friedrich Wiihelm Braun. 4to. Muuster: 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 muschelkalk 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 saurian or fish of 

 those triassic strata has been provided with a dentition adapted to crush 

 hard shells, like those of Terehmtula. 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. H. 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 E-oyal Society, the accuracy of which induction is corroborated 

 by the German palaeontologist. 



Apetyu Geologique du Departement de la Moselle. Par C. Pridrici, 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 

 ])upils who, after having followed our lessons, would wish to make in our 

 country application of that which they have learnt." Indeed, Monsieur 

 Pridrici, we have a respect for your humble little brochure, and if English 

 schoolmasters would do as much, and as well, for their pupils as you have 

 done for yours, 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. 



