189 



In a paper, — "de I'etage Bathonien et de ses sub-divisions 

 dans la Cote-d'Or,"* M. J. Maktin has given many details, 

 and a diagrammatic section of this stage, from which it appears 

 that the Bathonien, considered stratigraphically, is divisible 

 into six successive periods of deposits, separated from each 

 other by an equal number "d'arrets dans la sedimentation," 

 and which constitute so many "d'etages distinds." Studied in 

 descending order we find beneath the "Callovien zone a 

 Ammonites athleta" the following sub-divisions: — 



1st, — The strata with Pentacrinus Buvignieri, d'Orb., and 

 Heteropora conifera, Haime, of which the debris is found in 

 all points of the massif, becoming extremely abundant at the 

 last period of sedimentation. 



2nd, — Beds with Terehratula ohovata, Sow., and Isastrcea 

 limitata, Edw., which abound profusely in certain strata, and 

 are sparse in others. 



3rd, — Beds with Terehratula cardium, Sow., and Apiocrinites 

 Parkinsoni, Schloth., these fossils characterizing a limited 

 horizon comprised between the zone with Terehratula ohovata 

 above, and the Limestones with conchoidal fracture below. 



4th, — The thick-bedded Limestones, with Rhynchonella decorata, 

 d'Arch., which are considered by M. Payen to represent the 

 Great Oolite, and by M. G. de Neeville and others as the 

 Forest Marble. 



5th, — The oolitic Limestones, containing Pecten laminatus, 

 Sow., in abundance, a shell which is seldom found out of this 

 zone. 



6th, — The Marls, with Ostrea acuminata, Sow., which form 

 the base of the stage. This small curved oyster is very 

 abundant in the lower part of the zone and becomes rare in 

 the upper. 



Li summing up his observations on these sub-divisions M. 

 Martin observes, — "II y a mieux, non-seulement chacune de 

 ses periodes sedimentaires a vu se developper et puUuler durant 

 sa formation une ou plusieurs especes particulieres, mais encore 



• BuUetin de la Soc. Geol. de France, 2e Serie, t. xviii, p. 640 : 1861. 



