ANNIVERSARY ADDRESS OF THE PRESIDENT. IxXVU 



papers on the Geology of Portugal. This and some other of his 

 papers were confided to my care by Mr. Henry Sharpe, with the kind 

 belief that they might be useful to me in preparing my own address ; 

 but the only use I could possibly make of them is to set them 

 before you in their integrity, merely adding, where it appears ne- 

 cessary to do so, a few remarks of my own. 



Mr. Sharpe observes, that our knowledge of the geology of the 

 Peninsula has received a great addition from a memoir on Almaden 

 and the neighbouring mountains] by M. Casiano de Prado, which is 

 published in the * Bulletin of the Geological Society of France,' ac- 

 companied by full descriptions of the fossils by MM. De Verneuil 

 and Barrande. The following formations are described in this me- 

 moir. 



Lower Silurian {primordial zone of Barrande). — At Cortijos de 

 Malagou, in the mountains of Toledo, some fragments of a Trilobite 

 belonging to a new species of the genus Ellipsocephalus, found in a 

 quartzose sandstone, are considered by M. Barrande to indicate the 

 probable existence of this earliest fossiliferous zone in Spain ; it has 

 not yet been found in any other part of the Peninsula, and the 

 evidence of its existence at this spot must be still considered incom- 

 plete. 



Lower Silurian {second zone of Barrande). — The rocks belonging 

 to this part of the Silurian system are widely spread out in the centre 

 of Spain, and are very rich in organic remains. They are mostly 

 dark schists, frequently accompanied by quartzites : the fossils cor- 

 respond to a great degree with those collected in the Sierra de 

 Bussaco, in Portugal, by Senhor Carlos Ribeiro, and described by Mr. 

 D. Sharpe and Mr. Salter in the ninth volume of the Society's Journal ; 

 and, as in that locality, Trilobites and lamellibranchiate bivalves are 

 particularly abundant. Many of the Spanish species are found in 

 the west of France and in Bohemia, while comparatively few of the 

 English Silurian species occur in Spain ; thus strengthening the infer- 

 ence which had been drawn by Mr. Godwin-Austen from a similar 

 important fact previously announced, namely, that the ocean in which 

 the Lower Silurian beds were formed was divided, probably by inter- 

 vening land, into a northern and a southern area, which were peopled 

 in great part by different species of mollusks, a few species being 

 common to both regions. 



Among the organic remains, the obscure Fucoids (?) cdWedi'Bilohifes 

 by DeKay, deserve especial notice, as they characterize certain upper 

 beds of the Lower Silurian series, and in many parts afford the only 

 clue which the geologist has to a determination. 



Upper Silurian. — This part of the palaeozoic series is as feebly 

 represented in Spain as it is in Portugal, occurring here and there in 

 a schistose form, with Graptolites and Cardiola interrupta. There 

 are also in the Lower Silurian rocks of the Sierra Morena two spe- 

 cies, Chonetes striatella and Dalmanites DowningicSy which in the 

 North of Europe belong to the Upper Silurians. 



The Devonian series of beds, though scattered more irregularly 

 than the Silurian, are of great importance in the central mountains of 



