1800.] rniLLirs — sections near oxeokd. 



Section of the Strata at Culham, South of Oxford. 



Mixed gravel of Culham Fields 



309 





Ammonites dentatus 



Nodules 



Sandy and gravelly partings .... { 6^ 



JJasement-bed, pebbly and ferru- \ .... '>.-..- 



ginous. / *§■ 



Fine-grained sand, nearly uni- \ pj< 



form in composition. / . ,,'- 



Zone of fossils : Ammonites 



Brown nodules, with crystals i 

 (Bisulph. zinc, iu the cracks. J 



Ammonites 



Gault : blue laminated clay full 

 ol fossils. (20 feet seen.) 



• • . Lower Greewsand 



Green sand; cap of the Kimmeridge 

 Clay. (9 feet.) 



Kimmeridge Clay. (23 feet seen.) 



In descending from the gravelly surface-deposit, we have aboul 

 L0 feet of blue laminated clay, with the following fossils: — 



Ammonites dentatus. 



Ammonites lautus. 



l'clemnitcs minimus. 



Solarium conoideum. 



Rostellaria. 



Dentalium, probably D. decussation. 



Nucula pectinata. 



1 aoceramus concentricus | large I. 



Plicatula pectinoides. 



Pecten quinquesulcatus, 



Balanus. 



Cyclocyathus Fittoni. 



( loniferous wood. 



Below these onequivocal Gault layers, 1 1 » « - argillaceous deposits 

 are striated with short drift 1 .- 1 ? 1 1 i r i : i • of sand and small gravel. In 

 these, by careful search, I found specimens of the Ammonites men- 

 tioned above. These layers are about 5 feel thick, and gradually pass 

 upward into the ordinary Gault*. 



Below the-,,- Bandy layers is a more specially pebbly hand, in Borne 

 places compacted together, in which I found what Beems to be Pecten 

 orbicularis. This hand agrees in position with what may be termed 

 the basemenl bed of the Gault or the cap of the Lower Greensand 

 at Folkestone t. 



* In this part of the series, probably, occurred a Bne specimen "t Osfrta 

 macroptera, which came into the hands of mj friend Professor Walker, who 

 r. -i.l. - .ii Culham. 



' Sinoe the reading of tins paper, my friend Mr. Clulterbuck has found in 



