532 



J. E. BLAKE ON THE UPPER 



occasional calcareous band. The fossils at once indicate the horizon, 

 those noted being Amm. tricristatus. A. Martelli, Pholadomya an- 

 gustata, and Area rhomboiclalis ? '. Traced upwards these marls 

 become more calcareous and are almost limestones. They are there 

 crowded with Pholadomya paucicosta, and have also P.Jlabellata, Cer- 

 comya antica, Pinna lanceolata, a Trigonia like T.perlata, and Pecten 

 demissus. They become finally less fossiliferous, and are capped by 

 shelly limestones. This series may be traced with the same 

 character westwards to a great roadside quarry, where a face 

 of 40 feet of sandy limestone is worked, and .so on to Pacy, 

 where the well-known quarries have yielded many fossils, the 

 chief of which are Amm. cf. plicatilis, Belemnites ? Royeri, Pholado- 

 mya paucicosta, Myoconcha Rathieriana, Trigonia cf. irregularis, 

 Pecten demissus, Exogyra spiralis, and, according to Cotteau, Ostrea 

 dilatata. There can be no doubt that these rocks represent true 

 Oxfordian strata ; but their relation to those in the valley of Jully 

 has not been made out, though it is highly improbable that the 

 latter are older, as they contain, according to Leymerie and Raulin, 

 the characteristic fossils Ammonites perarmatus, Rhynchonella va- 

 rians, and Pecten Jibrosus, which have not been found here. The 

 numerous changes thus observed in the character of the rocks which 

 underlie the Corallian must be due either to an unconformity or 

 to a very variable development of the Oxfordian strata ; but we can 

 hardly accept the arrangement of the strata by the above-named 

 authors, who place the beds with Rhynchonella varians as the Lower 

 Oxfordian, while those at Ancy and Pacy are considered to be one 

 facies of the Middle Oxfordian, of which the other facies is the Coral 

 Rag, to be noted presently at Merry-sur-Yonne and elsewhere. The 

 next succeeding series in this district is a mass of lithographic lime- 

 stones, tending to split into thin plates, and for the most part un- 

 fossiliferous. Here and there, however, in its mass are fossiliferous 

 zones, apparently the representatives of strongly characterized beds 

 further to the east. The lowest of these has not actually been met 

 with ; but it is very instructively described by Cotteau (43), as seen 

 in the neighbourhood of Gland, where the following upward suc- 

 cession is determined: — (a) ferruginous Oxford clay ; (b) sponge-bed; 

 (c) limestones of Pacy ; (d) rubbly limestone ; (e) coral-bed, with 

 Pecten subarticulatus and Cidaris florigemma ; (f) lithographic lime- 

 stones ; (g) coralline limestone of Tonnerre. It is impossible not to 

 see in the beds e and d the continuation of those of Yannage and 

 the Cote d'Or, the succession being perfectly consonant to what 

 we might expect. There are, however, other bands in the litho- 

 graphic limestones nearer the summit, one of which is seen on the 

 roadside west of Commissey, associated with a rubble-bed ; another 

 occurs close to the village of Angy (below the white limestone), 

 where it was seen by Hebert (31), and considered to be a junction- 

 bed between the Corallian and Oxfordian, though lying upon one 

 great mass of lithographic limestone and covered by another. The 

 commonest fossil of this series is Rhynchonella corallina. This por- 

 tion, though, beiug more lithographic, it is less clearly characterized, 



