126 Scientific Intelligence. 
the Gulf of Murcia and isolated the Sierra Nevada and the mountains 
of Ronda, which then formed an island or a peninsula, separate from 
the continent. 
tute of the igneous products which during three consecutive periods 
were ejected through the granitic rocks of the plateau of Auvergne, 
and is ed by secondary rocks that are not found in the other; 
lower Silurian are precisely of the same age with the Llandeilo flags of 
Murchison or ‘Fauna Seconde” of Barrande. There has yet been dis- 
(p. 75) it is stated that the Peninsula limited on the north by the Pyrenees 
and the Cantabrian chain, is traversed obliquely from the E. N. E. to 
the W.S. W. by four systems of mountains; 1, the Sierra Guadarrama, 
which unites to the Sierras of Gredos, Gata and Estrella, and reaches 
quite to the ocean; 2, the mountains of Toledo; 3, the Sierra Morena, 
which extends into the promontory called Cape St. Vincent; 4, the 
high chain of the south coast which includes the Sierra Nevada, Tejeda, 
and Ronda. The chains may be presumed to be of different ages. 
he first 
the trias from the Paleozoic; the second, between - Jornaaie and 
trias; the third, between the miocene and nummulitic ; the fourth, be- 
wee tocene. The first is well seen near Horea 
and Checa. The second is observed at Albarracin, ete., where the 
