350 C. Dejperet — Oligocene of the Roanne Basin. 



Art. XXXI. — The Oligocene of the Roanne Basin and Its 

 Vertebrate Fauna /* by Charles Depeket. 



As shown by the studies of Le Terrier, the Tertiary basin 

 of the Roannais (a former province near Lyons, France) com- 

 prises a basal series of sands, gravels and clays, supposed to be 

 of Stampian age, and an upper series of calcareous marls cor- 

 responding to the Aquitanian, the whole being practically 

 barren of fossils. 



During recent years important paleontological discoveries 

 have been made in consequence of the extension of the earthen- 

 ware industry in the vicinity of Mayolet, Briennon, Mably, and 

 especially La Benissons-Dieu. For the purpose of arriving at 

 a more precise correlation of these deposits a reinvestigation 

 has been made by the present writer of the Oligocene strata as 

 they occur in the Roanne basin, where they form a monocline 

 dipping toward the northwest, and present the following sec- 

 tion (arranged in ascending order) : 



4. Calcareous marls of Saint-Germain-Lespinasse, extending 

 between that place and Digoin, and yielding at the latter locality 

 remains of an Anthracotherium characterized by having digits of 

 sub-equal length, and apparently belonging to the same species 

 as that which occurs at La Benissons-Dieu. 



3. Strata of Mably and La Benissons-Dieu, consisting of a 

 bottom bed of sands, which graduates upward into clays. From 

 the latter of these two localities have been obtained excellently 

 preserved remains (including the entire cranium, jaws, limbs, etc.) 

 of a large Anthracotherium, the lateral digits of which are much 

 less reduced than in A. magnum (—A. cf. bumbachense Stehlin). 

 There have also been found here two species of Aceratherium, 

 one of which is very large (A. filholi Osborn), the other very 

 small (A. albigense Roman) ; and besides these there occur 

 remains of a species of Gainotherium, one of Bremotherium, as 

 well as Crocodiles and Chelonians. 



2. Reddish clays of Briennon. These have yielded at Brien- 

 non remains of Entelodon magnum Aymard, and at Mayolet 

 an inferior molar of the small Anthracotherium alsaticum Cuvier. 



1. Nonfossiliferous bands of gravels, sands and conglomerates. 



The strata constituting the above section may be correlated 

 as follows : Divisions 1 and 2 are referable to the Sannoisian 

 (Lower Oligocene), the few known fossil forms being identical 

 with those occurring in the Lower Oligocene asphalt deposits 

 of Lobsann, in Alsace. Division 3, or the strata of Mably and 

 La Benissons-Dieu, corresponds to the lower portion of the 



* A preliminary notice, to be followed by a more detailed article in the 

 Bulletin de la Societe Geologique de France. Translated by C. E. Eastman, 

 Carnegie Museum, Pittsburgh, Penn. 



