110 REPORT—1850. 
together with the usual species well known in Belgium and England, such as Pro- 
ductus semireticulatus, P. punctatus, P. cora, Spirifer Mosquensis, &c. 
The existence in Spain of the Permian system is still a problem, as no fossils of 
that age have ever been found. Led, however, by the analogy of rocks and strati- 
graphical indications, Professor Naranjo y Garza has referred to that formation the 
red magnesian limestone and the gypsiferous marls of Montiel and of the lakes of 
Ruidera, where the river Guadiana rises. In the same group this author includes 
the famous cave of Montesinos in La Mancha, described by the immortal Cervantes 
as explored by Don Quixote. 
Secondary rocks.—Though equally deprived of fossils, the Trias is perhaps better 
known than the supposed Permian system. From the Pyrenees, where it is de- 
scribed by M. Dufresnoy, it may be traced to the provinces of Santander and 
Asturias, as well as to the kingdoin of Leon, on both sides of the Cantabrian chain. 
It does not contain the three series of rocks from which the name originated; and 
the muschelkalk being entirely wanting, it is reduced to marls and sandstones of 
red colour placed between the lias and the carboniferous strata. According to M. 
Casiano dé Prado, the same rocks occur in the mountains to the east of Madrid, 
where the Tagus has its source. 
The Jurassic and cretaceous formations extend over most of the eastern and 
southern part of Spain, covering vast areas in Catalonia, Aragon, Valencia, Murcia, 
Malaga and Ronda; lying upon the red sandstone, they constitute most of the high 
lands and mountains which to the east of Madrid make the divortia aquarum be- 
tween the Atlantic and the Mediterranean sea. In fact, they surround the central 
and more ancient parts, and may be traced to Portugal, where, according to Mr. 
Sharpe, they are principally confined to the littoral region. Along the Guadarrama, 
however, the chalk penetrates into the very heart of the country, extending south- 
west to Segovia, and crossing the high road from Madrid to Bayonne. 
M. de Verneuil thinks it will prove a hard task to separate the Jurassic and creta- 
ceous rocks of Spain; especially in the south, where the metamorphic action has 
produced so many alterations in the rocks, and has so obliterated the fossils. The 
difficulties will be about the same in the south of Spain, as those which have met 
the Italian geologists, and the districts of Malaga and Ronda seem to possess a geo- 
logical constitution very analogous to that of the Venetian Alps. _ In effect, beneath 
miocene and nummulitic rocks, rises a compact white limestone not to be distin- 
guished from the Italian scaglia and biancone, succeeded near Antequera and other 
places by a marble of reddish colour full of Ammonites, which may be compared 
to the Oxfordian Ammonitico rosso of the Italians. It is much used as an orna- 
ment in the churches of Malaga and Granada. 
In the eastern regions the task is more easy; and M. Casiano de Prado, by col- 
lecting good fossils, has already laid the foundations of a great work. Appointed 
by the Government to make a geological map of the province of Madrid, this ardent 
geologist has extended his investigations in the mountains in which the Xalon,, 
the Tajuna, the Tagus, and the Guadalaviar rise, and has ascertained that these 
mountains, more than 5000 feet high, are composed of triassic, Jurassic, and creta- 
ceous rocks. ‘The greatest part of the Jurassic fossils, as for instance at Siguenza 
and Alcolea, belong to the upper lias; viz. to beds characterized by the Ammonites 
Walcotti and Spirifer verrucosus. It is remarkable that most of the known Jurassic 
deposits of Spain belong to that subdivision. It is the case, for example, with those 
of the Sierra.de Moncay, in the province of Soria, and with those of the neigh- 
bourhood of Burgos. Little time has elapsed since the Jurassic group has been 
known in Spain, and for the progress of our knowledge respecting it we are spe- 
cially indebted to the researches of M. Ezquerra del Bayo and M. Schulz. In pre- 
paring a magnificent geological map of the Asturias, this last geologist had many 
opportunities of studying the Jurassic beds, which, being the prolongation of those 
of Santander and Bilboa, belong also in great part to the upper lias. 
The Oxfordian Jura occurs also in some provinces, as at Teruel; but at present 
the upper part of the oolitic series, or the Portlandian group, is unknown. The same 
may be said of the Neocomian rocks. The chalk of Spain appears to consist only 
of the hippuritic limestone (or beds equivalent to the lower chalk of England and 
France), and of a lower member, which, largely expanded in the provinces of San- 
