TRANSLATIONS AND NOTICES 



GEOLOGICAL MEMOIRS. 



Preliminary Notice on the Silurian System and the Trilobites of Bo- 

 hemia, By Joachim Barrande*. Pamphlet in 8vo. pp. 98. 

 Leipzic (Hirschfeld), 1846. 



The author states that he has often been asked during the long period 

 that he has studied the palaeozoic formations of Bohemia, "To what 

 epoch do you refer the ancient formations of the centre of Bohemia ?" 

 Having at length collected the necessary material, he is busily en- 

 gaged in preparing it for the public, under the title ' Systeme Silu- 

 rien du centre de la Boheme.' This title sufficiently indicates the 

 conclusion to which he has arrived with regard to the question al- 

 luded to. 



The purely geological evidence and the order of superposition, toge- 

 ther with a consideration of the lithological characters of the rocks, 

 would however hardly be sufficient to produce conviction on this 

 subject. These characters are necessarily uncertain, and we must 

 have recourse to the palaeontological characters to justify the classi- 

 fication adopted. 



In the present pamphlet the author does not propose to pass in 

 review all the members of the palaeozoic fauna, since this would re- 

 quire greater space. He limits himself to those most characteristic. 



The Trilobites are generally admitted to be the fossils which may 

 most usefully be employed to determine the relative age of the ancient 

 formations. Such fossils here require special attention, since they are 

 very numerously represented in Bohemia. In the narrow limits of 

 the present sketch no minute description is admissible, and the 

 object is to establish a parallel between the ancient formations of 

 Bohemia and those of other countries already known. It is there- 

 fore held sufficient merely to mention the genera and species, very 

 slightly alluding to the principal characters which distinguish them. 



The palaeozoic rocks of the centre of Bohemia occupy a well-de- 



* Notice prelitninaire sur le systeme Silurien et les Trilobites de Boheme, par 

 Joachim Barrande. Leipzic, 1846. 



VOL. III.— PART II. E 



