Giraud-Soulavie 205 



assemblage of fossil shells. The first of these ages, he 

 declared, was represented by limestone containing organic 

 remains with no living analogues, such as ammonites, 

 belemnites, terebratulse, gryphites, etc. Having no more 

 ancient strata in the district, the Abbe called this oldest 

 limestone primordial. His second age was indicated by 

 limestone, in which the fossils of the preceding epoch were 

 still found, but associated with some others now living in 

 our seas. Among the new forms of life that appeared in 

 these secondary strata he enumerated chamas, mussels, 

 comb-shells, nautili, etc. These, he said, inhabited the 

 sea, together with survivors from the first age, but the 

 latter at the end of the second age disappeared. Above 

 their remains other races established themselves, and 

 carried on the succession of organized beings. 



The third age was one in which the shells were ol 

 recent forms, with descendants that inhabit our present 

 seas. The remains of these shells were found in a soft 

 white limestone, but not a trace of ammonite, belemnite, 

 or gryphite was to be seen associated with them. Among 

 the organisms named by the Abbe were limpets, whelks, 

 volutes, oysters, sea-urchins, and others, the number of 

 species increasing with the comparative recentness of the 

 formation. He thought that the most ancient deposits 

 had been accumulated at the highest levels, when the sea 

 covered the whole region, and that, as the waters sank, 

 successively younger formations were laid down at lower 

 and lower levels. 



From the occurrence of worn pebbles of basalt in the 

 third limestone, Giraud-Soulavie inferred that volcanic 

 eruptions had preceded that formation, and that an 



