THE EVOLUTION OF THE TERTIARY MAMMALS, 

 AND THE IMPORTANCE OF THEIR 

 MIGRATIONS 1 



PROFESSOR CHARLES DEPERET 



Second Paper. Oligocene Epoch 2 

 Having analyzed the local evolution and the migrations 

 of the Eocene mammals (Comptes rendus, 6 novembre, 

 1905), I will now consider the corresponding data in 

 regard to the Oligocene. 

 B. Oligocene Faunje. 



I. Lower Oligocene (Sannoisian or Lower Tongrian). 

 Two successive fauna?,: 



(a) Fauna of the white marl of Pantin, Romainville. 

 The fauna of the lignites of Celas, Avejan, Vermeil 

 (Gard), of the limestone of Brunstatt and of Rixheim 

 (Alsace) are probably not very distant from this. With- 

 out doubt the same is also true of several deposits in the 

 South West of France: Fronsac and la Grave (Gironde), 

 Sainte-Sabine, Duras, Issigeac, Saint-Cernin (Dordogne). 

 A part of the phosphorites of Quercy, 3 and of the "ter- 

 rain siderolithique" of Fronstetten (Suabia) belong to 

 the same level. 



1. Local Evolution.— Continuance of the Palseotheriidae 

 (Palaeotherium, Plagiolophus), of the Anoplotheridae (last 

 of Anoplotherium), of the Xiphodontidae (last Xipho- 

 don), of the Rodentia— Theridomyidse ( Theridomys ) . 



1 First paper, Eocene Epoch, in the February number of the Naturalist. 



2 Extract from the Comptes rendus des seances de I'Academie des Sci- 

 ences, t. CXLH, p. 618 (seance du 12 Mars, 1906). Translated by Johanna 

 Kroeber. 



3 The remarkable fauna of the phosphorites is not a homogeneous assem- 

 blage, but a composite representing horizons from the Bartonian to the 

 Stampian, inclusive. In general, therefore, I shall consider only those 

 genera of the phosphorites that have been found elsewhere in the stratified 

 deposits, and whose age can thus be positively determined. 



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