ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixi 



already stated in a former communication (see Quarterly Journal of the 

 Geological Society, vol. viii. p. 182), and pointing out how completely 

 the whole sequence of the Upper and Lower Silurians of Great Britain 

 is represented in this thinner development of the Norwegian district. 

 Even the great Russian empire, he observes, does not exhibit so per- 

 fect and clear a succession of the Paleozoic formations as this Nor- 

 wegian trough in the parallel of Clnistiania. 



Since this communication was read, I find that M. Kjerulf s views 

 have been fully published at Christiania by Adolph Strecker in a 

 work entitled ' Das Christiania-Silur-Becken' (the Silurian Basin of 

 Christiania) chemically and geologically examined, by Theodor Kje- 

 rulf. The map communicated by Sir R. Murchison belongs to this 

 work, the greater portion of which is occupied with chemical analyses 

 of the different rocks in the district. The results of these inquiries, 

 instead of clashing with the geognostic observations, as some persons 

 might perhaps have feared, have not only confirmed them, but have 

 established the universality of the law respecting the formation of 

 volcanic rocks already laid down by Prof. Bunsen *, who has divided 

 all igneous rocks into two classes, the trachytic and the augitic or 

 pyroxenic. 



Amongst the many valuable additions to paleeontographical geo- 

 logy, I must mention the memoir of MM. de Koninck and Le Hon, 

 *'0n the Crinoidea of the Carboniferous Formation of Belgium," 

 originally published in the Collection of Memoirs of the Royal Aca- 

 demy of Belgium. So rapid has been the progress of discovery in 

 this branch of our science, that whereas in 1842 one of the authors 

 of this paper could only procure from these beds fifteen species of 

 Crinoidea, they have now been able, partly by their own exertions 

 and partly by the aid of numerous friends, to bring together fifty- 

 three species. These belong to eleven genera, four of which are 

 entirely new. They are derived partly from the Carboniferous lime- 

 stone, which forms the basis of the formation in Belgium, and partly 

 from the overlying beds of limestone and its associated clays. The 

 perfect state of preservation in which most of them were found, has 

 enabled the authors to correct and modify the opinions which have 

 hitherto prevailed respecting the organization and habits of these 

 singular animals. 



The authors commence their work with a most imposing list in 

 chronological order, commencing with 1558, of authors who have 

 written on the Crinoidea. No less than 346 works are quoted, con- 

 taining more or less reference to the subject. A mass of literature 

 so overwhelming was probably never before quoted in reference to 

 one single subject. This is then followed by a special historical ac- 

 count of the progress of knowledge on the subject of the Crinoidea 

 in general, in which the authors confess that, notwithstanding all that 

 has been written, the question is still involved in obscurity on many 

 points, the removal of which they leave to those who may have more 

 materials at their disposal. 



* " Ueber die Processe der vulkanischen Gesteins-bildungen Islands." Pogg. 

 Ann. vol. 83. p. 1. 



