The object of this work is the study of the artiodactyls of the karstic locality of Lissieu near Lyon. Among the sixteen species counted, five (Hyperdichobune nobilis, Hyperdichobune sp., Haplabunodon mulleri, Tapirulus depereti and Pseudamphimeryx schlosseri) are cited for the first time in this fauna. The description of part of the anterior dentition of «Dichobune» langi permits the referal of this species to the genus Hyperdichobune. The new selenodont species Dichodon lugdunensis  described in this work belongs, with its ancestor Dichodon simplex, to a lineage distinct from that of Dichodan cartieri and Dichodon ruetimeyeri. Finally, the taxonomic reality of the Lissieu species, Lophiobunodon rhodanicum Deperet, is justified. All the other species have been compared with those of Egerkingen. Even though with most of them no difference in age can be shown between the two deposits, some however indicate clearly by their degree of evolution that Lissieu is slightly more recent than Egerkingen. ln the history of Eocene mammals, the Lissieu fauna, because of its homogeneity, can be considered as a sure reference fauna of the Auversian period. 

Two steps can be distinguished in the history of the first invasion of western and south western Europe by the arvicolines. The first step corresponds to the installation of these rodents with the immigration of Promimonys inxuliferus Kowalski, then of Mimomys stehlini Kormos and of Mimomys gracilis (Kretzoi). The second is characterized by the establishment of a geographic differentiation in the arvicoline fauna between the south of France and Spain, from where are described new species of Mimomys (Mimamys cappettai, Mimomys septimanus, Mimonys medasensis), and the rest of France, where are found only elements already known from central Europe or England (Mimomys polonicus Kowalski, Mimomys pliocaenicus F. Major, Mimomys reidi Hinton, or forms very close to the latter). This geographic differentiation, which is very certainly the consequence of the division of Europe into distinct climatic provinces, one of them being the southern province comprising at least Spain and southern France, could result from a cladogenetic evolution of Mimomys stehlini and Mimomys gracilis after their immigration. The present work is also a contribution to the search for correlations between the diverse micromammal localities of the latest Pliocene (or early Villafranchian) and of the early Quaternary of Europe.