470 Notices of Memoirs — 



Upper Eocene — 



/. Fauna of the phosphorites of Caylux (age of the Limestone of Brie). — 



Distinguished from tlie preceding by the increase of the Etitdedon, the great 



Anthiacotheriuniy the CainotJiermni, contemporary with the Anoploihcnum 



and Falaotherimn. 

 vt. Fauna of the gypsum of Paris, of Bembridge, and of the lignites of Debruge. 



— Distinguished from the preceding by the absence or rarity of Lophiodon. 



Keign of Palmoiherium, Ano.plotheriicm, Chm-opotanms, Dichobime, Xiphodon, 



HyiEnodon, and Pterodon. 



Middle Eocene — 



n. Fauna of Hordwell and Mauremont (age of Sands of Beauchamp). — Dichodon, 



MicrochcE7'us, Rhagatherium. Tire appearance of the PalcEotheriiim Avith 



the Lophiodon. 

 o. Fauna of Egerkingen, Argenton, Issel, and Calcaire Grossier of Paris. Reign 



of Lophiodon and Packynolqphiis. 



Lower Eocene — 

 p. Fauna of London Clay. — Hyracotherium, PliolopJms. 

 y. Fauna of the Plastic Clay of Soissonnais. — Coryphodon, Palaonictis, 

 r. Fauna of the grits of La Fere. — Arctocyon. 



IV.- — -From the preceding summary it will be seen that tlie fauna 

 ef Eppelsheim must have had a different facies from those of Leberon 

 and Pikermi, because it contained neither Hyeena, Hellacloth^rium, 

 Giraife, nor those great herds of Antelopes which gave an Afiican 

 aspect to the faunas of Leberon ^nd Pikermi. But with these 

 contrasts we find identical species in the deposits of Germany, 

 Greece, and Provence ; all the faunas of the Upper Miocen-e of 

 Europe represent degrees of evolution so related, that at first it is 

 difficult to say which has been the more ancient. M. Gaudry con- 

 siders that the difference of age between the two sub-divisions of 

 the Upper Miocene is but trifling, and that the different faunas may 

 be attributed in part to the changes in the physical features of the 

 surface which altered the habitats of the animals, and occasioned the 

 displacement of the faunas. For in supposing that the organic world 

 has gradually progressed, if geologists find sudden ajDpearanoes of 

 fossils in passing from one stage to another, it is because they have 

 in general placed the limits on points where there have been dis- 

 placements of faunas. The palaeontologist, who does not believe in 

 migrations and local extinctions, seeks in vain to connect the chain 

 of ancient beings ; he finds appearances, disappearances, and recur- 

 rences without bfring able to explain them. 



V. — From the reasons given in the preceding paragraph it would 

 be iiseless to seek in the same country for an uninterrupted chain of 

 fossil beings ; to find such a chain we must uncover all the strata 

 of the earth. But if in passing from one stage to another we per- 

 ceive breaks, we find also analogous forms. Thus, in comparing the 

 Mammalia of the Upper with the Lower Miocene, we find — Simocyon 

 analogous to AmpMcyon, Ictitlierium Orhignyi to Viverra, Macliai- 

 rodus cultridens to M. palmidens, Ancylotherium to Macrotherium, 

 Mastodon longirostris and PenteUci to M. angustidens, ItMnoceros 

 Schleiermacheri to B. Sansaniensis, Siis palceochcerus to S. clmroides, 

 Clialicoiherium to Anisodon, Dicrocerus anocerus to D. Aurelianensis, 

 Gazella deperdita and hrevicorms to G. Martiniana. Many Pliocene 



