J. F. BLAKE ON THE KIMMERIDGE CLAY OF ENGLAND. 



209 



Ammonites Berryeri, Les. 



cymodoce, jD' Orb. 



— : — decipiens, Sow. 

 —— serratus, Sow. 

 Belemnites nitidus, Dollf. (young). 

 Cerithium forticostatum, Bla. 

 Serpula tetragona, Sow. 

 Nucula Menkii, Bom. 



Nucula obliquata, Bla. 

 Astarte supracorallina, JD' Orb. 



Michaudiana, D'Orb. 



pesolina, Cont. 



Inoceramus expansus, Bla. 

 Cyprina cyreniformis, Bla. 

 Lingula oyalis, Sow. 



The number of pits on this horizon and their wide separation 

 seem to indicate considerable total thickness. They may be con- 

 sidered to form a second subzone. Exposures of beds below this 

 level exhibit, as remarked by Mr. Judd, a well-marked dif- 

 ference, both lithologically and palaeontologically, but still not 

 sufficient to warrant a separation, though the difference is far more 

 marked than anywhere else below the Upper Kimmeridge, in 

 Lincolnshire — so much so that the first time I saw these lower beds 

 after seeing those of Market Easen I took them to be Oxford Clay. 

 This was at a well-sinking on the Bishopsbridge Road, about 1| mile 

 east of the pit last mentioned. Here were black clays with white 

 rotten fossils in layers, most of them being undistinguishable 

 (apparently Pholadomyce) ; but Ostrea dilatata and Belemnites were 

 plentiful; and there were some reptilian remains, consisting of very 

 compressed vertebrae and long bones. On one of these, however, 

 were numerous Discince, which, though badly preserved, showed the 

 fine radiating striae of Discina Humphresiana. The Belemnites too 

 were not hastate, but comparable with B. nitidus. However, the 

 age was settled on discovering in a cutting, west of the Wrawby 

 cutting before mentioned, exactly similar black clays in the same 

 stratigraphical position, containing also Ostrea dilatata and deltoidea 

 and abundance of Belemnites nitidus, associated with : — 



Ammonites, sp. (? young of deci- 

 piens). 

 Bissoa mosensis, Buv. 

 Area minuscula, Cont. 

 Anatina minuta, Bla. 

 Serpula tetragona, Sow. 



Trigonia, sp. (cast, elongated). 

 Nucula Menkii?, Bom. 

 Corbula Deshayesia, Buv. 

 Anomia Dollfusii, Bla. 

 Lima gedilignensis, Bla. 



Some of these which do not occur higher up are seen again, with 

 Ostrea deltoidea, at Woodhall Spa. It is plain therefore that in 

 this locality 0. dilatata is associated with, and almost takes the 

 place of, that oyster. 



Passing towards the south, the brickyard west of West Brank- 

 with, near Wragby, seems to be in this region from the multitude 

 of fragments of oysters, showing the curving round of the band of 

 similar strata to the S.E., and the low level in which the Langton 

 pit is dug. 



To the south, again, at Hawkstead Hall (five miles south-west of 

 Horn castle), a small pit exposes gypsiferous clays (the lower zone), 

 with septarian and rather bituminous nodules. These contain, in 

 abundance, a peculiar form of Amm. serratus (like Sowerby's ori- 

 ginal), with Belemnites nitidus and Ostrea deltoidea. 



The pit at "Woodhall Spa, a mile to the south, is much more 



