ANNIVERSARY ADDRESS OF THE PRESIDENT. Ivii 



and other igneous rocks, as well as by the metamorphism which 

 large masses have undergone. • Sir R. Murchison, however, expressed 

 his belief that all the members of the Devonian group of the Rhenish 

 Grauwacke of the Germans, from the Spirifer Sandstone and Slate 

 upwards, through the Stringocephalus and Eifcl Limestone, to the 

 Upper or Clymenia Limestone, are there present ; and that they are 

 succeeded by schists often in the siliceous state of Kiesel Schiefer, 

 and by others containing the well-known Posidonomya Becheri of 

 Herborn ; whilst rocks of this Lower Carboniferous age occasionally 

 contain a dark limestone, with characteristic fossils of the Mountain 

 Limestone. M. Adolphe Roemer, who has partly worked out this 

 comparison, is still engaged on that work, and in completing a 

 geological map of the district. 



The chief object of Sir R. Murchison's last visit to the Hartz was 

 to determine whether certain rocks in its eastern extremity, which 

 have been laid down and mapped as Silurian by M. A. Roemer, were 

 really of that age or not ; an interesting question, inasmuch as it was 

 precisely in this portion of the district that Professor Sedgwick and 

 the author anticipated fifteen years ago that the oldest rocks of the 

 chain would be found. It appears that in one small boss of lime- 

 stone, not exceeding ten feet in thickness, and subordinate to the 

 slates on the north-east flank of the mountain, M. Jasche of Elsin- 

 berg has discovered many fossils of the genera Orthis, Terebratula, 

 Leptoina, Spirifer, Pentamerus, Trilobites, &c., some of which are 

 undoubtedly British Upper Silurian species, while others are identi- 

 fied with Bohemian fossils described by Barrande as belonging to his 

 uppermost stages. Looking to the mineral aspect of these schists 

 and limestones, which differ from all others in the Hartz, and judging 

 from the fossils, the greater number of which are of types apparently 

 more ancient than those of any known Devonian rock. Sir R. Mur- 

 chison suggests that the grauwacke round Harz-gerode may be re- 

 ferred to the uppermost Silurian rock of the Continent, and be placed 

 on the same parallel as one of the highest stages of M. Barrande. 



In the Rhenish country Sir R. Murchison and Prof. Morris found 

 that the Wissenbach and Caub Slates had been perfectly identified 

 by Dr. Sandberger and his brother by means of a community of 

 fossils, and that Chjmenia had been detected in the Cypridina Slates 

 of Nassau, thus identifying these rocks with the Krammenzel-stein 

 of Westphalia. But the most striking new discovery in this region 

 was one which Sir R. Murchison regretted he was unacquainted with 

 when he published his *Siluria,' viz. that the quartz rocks of the 

 Taunus, about whose true place in the series there has been so much 

 discussion, prove to be the youngest of all the older rocks on the 

 right bank of the Rhine. In their trend to the E.N.E. they part 

 with this highly metamorphosed character, and, being regularly 

 bedded and interstratified with shale, have been there shown by 

 ]M. Ludwig of Nauheim to overlie the series of Devonian rocks, con- 

 sisting in ascending order of slates, Spirifer sandstones, Wissenbach 

 slates, Eifel limestones, &c. In these overlying quartzites large 

 plants like Calamites have been discovered, and as they lie trans- 



