IO2 HISTORY OF GEOLOGY AND PALAEONTOLOGY. 



Palassou wrote the first full scientific description of the geolo- 

 gical structure of the Pyrenees. He worked nearly forty 

 years in this district, and in 1782 published his Essay on the 

 Mineralogy of the Pyrenees Mountains. The work comprises 

 eight mineralogical maps on a large scale, and twelve plates 

 with panoramic views. After the precedent of Guettard, Palas- 

 sou used special symbols to distinguish the different rocks 

 and minerals on the maps; and took careful observations 

 of the. strike and dip. Palassou concluded that the whole 

 mountain-chain .is made, up of limestone, shales, clay, and 

 granite, with a general strike in W.N.W. and E.S.E. direc- 

 tion, an.d he gave. a number of transverse sections displaying 

 a simple and uniform structure throughout the chain. 



Palassou's work was based upon principles which were 

 already somewhat antiquated when the work appeared. He 

 believed that the sedimentary rocks had been deposited in the 

 various inclined and horizontal positions in which he found 

 them. Limestones and fossiliferous shapes of all ages were 

 termed Secondary formations; no attempt was made by 

 Palassou to determine systematic sub-divisions according 

 to the rock varieties, the fossils, or any other individual 

 feature, and he discarded the "transitional" series of forma- 

 tions between the primitive granitic rocks and the Secondary 

 formation. 



Among the varieties of rock a diabasic rock containing 

 uralite was described for the first time under the name of 

 Ophite. 



An engineer, Picot de Lapeirouse, published a finely illus- 

 trated work on the Rudistes or Hippuritidse, a fossil Lamelli- 

 branch family represented in great numbers of individuals in 

 the Cretaceous deposits of the Pyrenees. This remarkable 

 genus had been discovered by Abbe Sauvage in the Cevennes 

 mountains forty years previously. Unfortunately Lapeirouse, 

 beautiful as his illustrations are, entirely misjudged the place 

 of these fossils in the animal world, and called his work A 

 Description of several new kinds of Orthoceratites Ostradtes 

 (Erlangen, 1781). 



Ramond de Carbonnieres contributed several geological and 

 palseontological works on the Pyrenees. He was an enthusi- 

 astic mountaineer and made a special examination of Mont 

 Perdu, which was then thought to be the highest summit of 

 the chain. He proved that this summit was not composed of 



