JURASSIC OF THE PARIS BASIX. 



561 



socardia elegans, Trigonia monilifera, Area Sauvagei, Cucullcea 

 (called quadrisulca, de Lor.), Area rhomboidalis, de Lor., Gastro- 

 chcEna boucardensis, Nucula cequilatera, Astarte Sauvagei, A. num- 

 mus, A. bruta, Litliodomus inclusus (in Isastrcea), Modiola azqjui- 

 plicata, Mytilus pectinatus, Lima proboscidea, Pecten vimineus, P. 

 intertextus, Avicula oxyptera, Plicatula horrida, Exogyra nana, 

 Ostrea rastellaris, Terebratula tetragonal, Rhynchonella eorallina, 

 Thecosmilia sp., Serpida Royeri,Cidaris florigemma, C. Smithii, Pen- 

 tacrinus cingulatus '?. These fossils being collected from the surface- 

 stones, it is quite possible that some may be derived from overlying 

 beds, which would account for their only being recorded by de Loriol 

 as from such. But when we consider also the more important fossils 

 recorded by him in addition to those above, such as Belemnites nitidus, 

 Anatina striata, Astarte Micliaudiana, Opis Phillipsii, Area texta, 

 Hinnites fallax, and Hemiciclaris intermedia, we see that there is a 

 very feeble minority, almost an absence, of Oxfordian species, and that 

 the whole indicates a higher horizon than the usual florigemma-i&g. 

 If it be a remanie deposit, it might well be formed by the breaking- 

 up of beds overlyiug the Coral Rag of Brucdale. The marly beds in 

 situ which, with the above exception, continue upwards at the Mont 

 des Boucards the clays overlying the 0/r*s-limestone, are well seen 

 in cuttings and quarries on the hill-side. Only here and there they 

 have hard bands ; and the term " limestones " is quite deceptive. 

 Only one soft chalky limestone caps the whole, and forms the top of C 

 of M. Pellat. At the base these beds are crowded with Terebratula 

 insignis and Rhy aclionella corallina (quite a repetition of the chalky 

 limestones of Bourges), and here and there are lumachelles of Ostrea 

 nana, and occasional deltoid oysters ; Mytilus pectinatus and Ostrea 

 solitaria {rastellaris) are also abundant. The other fossils observed are 

 Ammonites boncardensis [?], Nucula Menkei, Cardium Bufrenoycum, 

 and Astarte nummus. A total of fifty-one species is recorded from the 

 basal portion by de Loriol, an examination of which shows the same 

 tendency as the above, namely to associate these with true Supra- 

 coralline beds, or at most with the highest part of the Coral Rag, and 

 to make it difficult to conceive how any one could have taken them 

 for Oxfordian. The upper portion, C of M. Pellat, is, above all things, 

 characterized by the presence of Ceromya excentriea, Isocardia striata, 

 and Mytilus perplicatus, fossils which are everywhere more Astar- 

 tian than Corallian ; the others noted are Area rliomboidalis, de Lor., 

 Cardium intextum, G. oriliogonale, Pleuromya tellina, and Exogyra 

 bruntutana, which have little effect on the correlation. These marls 

 are followed by more dark clays till the ferruginous grits are reached. 

 In the third locality, that of Brucdale and the neighbourhood, are 

 seen at the base 6 or 8 feet of Coral Rag in situ, with the TJiam- 

 nastrceai in their place of growth ; but the whole thickness is not seen, 

 nor any thing below the Rag. The fauna is an ordinary Rag one, incra- 

 ding Cidaris florigemma and various Gasteropods and Limce. There is 

 certainly some difference between it aud that of the coral stones of the 

 Mont des Boucards. This is doubtless largely due to want of search 

 among the latter ; yet what difference there is indicates a higher 

 Q.J.G.S. No. 148. 2p 



