The theory of earth -- Living and fossil elephants -- The megatherium from South America -- A research program on fossil bones -- An appeal for international collaboration -- The animals from the gypsum beds around Paris -- A pouched marsupial from Paris -- Popular lectures on geology -- A review of fossil pachyderms -- A report on André's theory of the earth -- The progress of geological science -- The geology of the region around Paris -- Fossil deer and cattle -- Collected researches on fossil bones -- The revolutions of the globe -- Conclusions.