Chap. XVII] CARBONIFEROUS AND SILURIAN IN PORTUGAL. 421 
The question, indeed, was thus settled whilst the first edition of this work 
was printing; for Mr. Sharpe then communicated to the Geological Society of 
London * the discovery of fossils, accompanied by important observations made 
by M. Carlos Ribeiro, which showed the prolongation of the same axis of Silu- 
rian rocks from north-north-west to south-south-east, far beyond the Douro. 
The rocks in question form, in fact, the crest of the Serra de Busaco, on which 
Wellington and Massena first tried their strength, and thence extend to the 
south-south-east beyond the River Mondegot into the Serra de Mucella. During 
the greater part of their course, the Silurian rocks are surrounded or flanked by 
older unfossiliferous masses, consisting of mica- and chlorite-schists with clay- 
slate &c. These crystalline rocks are at once followed by dark-brown indurated 
shales, somewhat slaty, which abound with Lower-Silurian fossils, among which 
Mr. Sharpe recognized numerous species of Leptsena and Orthis, with Trilobites, 
many of them previously undescribed. He identified indeed the most charac- 
teristic of the Trilobites with species well known elsewhere — Trinucleus Pon- 
gerardi, Calymene Tristani, and C. Arago of Brittany, also Phacops socialis of 
Bohemia. The lower fossiliferous rock of Busaco therefore obviously represented 
the oldestzone in France and Spain then known to contain remains, and was identi- 
cal with that described by Mr. Sharpe at Vallongo near Oporto. That zone is sur- 
mounted, and chiefly along the middle of the ridge of Busaco, by a band of hard 
ochreous shale/frequently altered by eruptive masses of greenstone and generally 
breaking up into prisms, the bedding being scarcely distinguishable. This rock, 
probably equivalent to the sandstone of May in Normandy, is full of small Corals, 
such as Favosites fibrosus, besides species of Retepora (?), also many simple- 
plaited Orthides, and some Trilobites common to the subjacent deposit, — the 
whole of the evidence proving clearly that it is simply a superior member of 
the Lower Silurian group. In short, the uppermost of these Silurian rocks in 
Portugal is apparently the same zone we have been considering in Spain and 
France — viz. a bluish shale or argillaceous schist, containing the well-known 
British fossils Graptolites Ludensis and Cardiola interrupta, with other Mollusks, 
also numerous crushed specimens of Orthoceratites. 
Now all these Silurian rocks are overlain unconformably by a deposit of true 
Carboniferous age, the shales and sandstones being full of Ferns and other 
Plants of species common in the Coal-deposits of France and Germany. Thus, 
when traced out, the apparent anomaly at Vallongo was resolved by a case per- 
fectly analogous to the examples given in previous parts of this work, and the 
order of succession was proved to be the same as in other regions. 
The exact age of many of the crystalline stratified rocks which form the hilly 
and mountainous region separating Portugal from Spain, and wrapping round 
the north of the former country, has not yet been accurately defined. That 
many of them are the metamorphosed varieties of the Silurian and other Palaeo- 
zoic rocks under consideration is almost certain. In parts of Portugal they are 
richly metalliferous ; and some of their products have been well described by 
J. A. C. das Neves Cabral, who acted as the Commissioner of the Portuguese 
Government at the International Exhibition in London in 1862. 
Sardinia and Upper Italy. — Extending our inquiry eastwards from Northern 
Portugal and Central Spain to like parallels of latitude on the other side of the 
* Quart. Journ. G-eol. Soc. Lond. vol. is. p. 135. Iberian Peninsula. After the victories in Portu- 
t The author craves pardon of the reader for gal he was in that Division of the Army, under Sir 
stating that, when a young Ensign (sixteen years John Moore, which marched through so large a 
of age) in the 36th Regiment, he disembarked, on portion of Spain from Badaj os to the Escorial, 
the 1st of August, 1808, at the mouth of this Eiver and thence northwards, terminating in the retreat 
Mondego, and close to the boat from which Sir to Corunna. 
A. Wellesley first stepped on the shore of the 
