316 Dr. FiTTON on the Strata below the Chalk. 



Cliff, where its occurrence is mentioned by Mr. R. C. Taylor ; and Mr. Woodward states, that 

 beneath 13 feet of brick-earth, near the former place, a few inches of bituminous shale were 

 found, which burned readily and contained between its laminae impressions of an Ammonite, and 

 a small bivalve, (Tellina?). * 



At Southrey, I found in the clay many of the characteristic Kimmeridge fossils, among which 

 are Ostrea deltoidea, Ammonites Lamberti, Aptychus, like that of Buckinghamshire (PI. XXIII. 

 fig. 1 1.), and a Vermetus ; with fragments of the teeth and bones of Saurians. 



In a brick-field beneath Downham Market, where 5 or 6 feet of clay were exposed, I found 

 Ostrea deltoidea, another large bivalve, and a great number of Ammonites (^A. biptexl) much com- 

 pressed. In a section at Denver Sluice, near Downham, the order was as foUowsf : — 



Ft. In. 



1. Sandy loam, peat and clay ; containing roots of plants = 23 



2. Dark ferruginous sand 3 



3. Clay ; which, from its position and contact with sand, seems to be that of Kim- 1 7 /% 



meridge J 



The Oxford oolite has not been found in this part of the country ; nor the subjacent calca- 

 reous grit. 



The only mode, therefore, in which the presence of the Oxford clay can be ascertained, is by 

 its fossils ; for, although the great depth of clay passed through at Lynn, in the well sunk and 

 bored at Mr. Allen's brewery, exceeds the average thickness of the Kimmeridge clay, even when 

 combined with the Weymouth strata, identity cannot be safely denied, on the evidence of thick- 

 ness alone. More than 630 feet of clay were cut through in this well, after passing through 

 between 40 and 50 feet of loam, peat, clay, and marine silt. Of this great thickness a part 

 no doubt belongs to the Kimmeridge clay ; and the fossils obtained from the lower beds, now 

 in Mr. Rose's possession, offer no very decisive proof that the Oxford clay is there. But on 

 the other hand, none of the more characteristic fossils of Kimmeridge occur in it, except, 

 Ostrea deltoidea; — no Gryphcea Virgula, nor Aptychus. The list given by Mr. Rose, includes 

 Ammonites decipiens ; A. excavatus, and another very small species ; Belemnites abbreviatus ; 

 Gryphcea hullata, with Serpula tricarinata attached to it ; Mya depressa (a Kimmeridge clay 

 fossil?) ; a Pecten impressed upon a Venus ; and a muricated spine of an Echinus. Among the 

 specimens from the deep well which I find mentioned in my notes of 1827, are a large Ammonite ; 

 two others of small size (one very like A. Kelloviensis); Gryphcea dilatata, with another bivalve 

 adhering ; Ostrea deltoidea ; two indistinct bivalves ; and part of a flat bone. 



( 162.) List of Fossils of the Beds below the Chalk, in Bedfordshire, 

 Cambridgeshire, and Norfolk. 



Gault : — including the red stratum at Hunstanton. 



Ammonites dentatus. Ingoldsthorpe, Norfolk : in grey sandy clay. 



A inflatus. young. Between Cambridge and Ely. 



A lautus. Between Cambridge and Ely : in green sand, at the bottom of the 



Gault. 

 A varicosui. Between Cambridge and Ely ? 



* Rose, p. UG. -j- Ibid., p. 173. 



