110 F. L. Kitchin and J. Pringle — 



to the basement-bed of the Upper Gault and to the basement-bed 

 of the Cenomanian stage, as understood by English geologists 

 (sub-zone of Catopygus colmnharius). 



(2) The Cenomanian bed is present in the form of isolated lenticles 

 of limestone. Although no comparable stratum can be found at 

 the j)resent outcrop, which has receded from the area where con- 

 ditions produced this particular type of deposit, the bed has a close 

 lithological counterpart in Northern France (Matringhem), where 

 there is an almost identical bed at the base of the varians zone. 



(3) At Harris's Pit the Cenomanian bed, an inconstant layer of 

 Upper Greensand formerly seen above it, and an overlying mass of 

 Gault Clay of rostratus age are in an inverted order of succession. 

 There is a junction of erosion and non-sequence between the Gault 

 and the Cenomanian bed. 



(4) The normal unbroken passage from Lower Greensand to 

 Lower Gault {interruptus zone) is shown south of Leighton Buzzard 

 in more complete development than in other sections hitherto 

 described in this country. The series here includes a sandy passage- 

 bed of tardefwcata age (with the Leymenella-ia,una) overlain by 

 interruptus clay, as in parts of the Continent. 



(5) The Lower Gault has not been seen at Shenley Hill, where 

 there is an overlap of Upper Gault upon the Lower Greensand. 

 The basal bed of the Upper Gault is here of mixed and variable 

 constitution, with much coarse material, containing relics of the 

 denudation of the tardefurcata bed. It passes up first into clay, 

 then into more marly clay containing ,the early rostratus fauna 

 of Bed IX of Folkestone, the highest Gault as yet seen at Shenley 

 Hill in situ. The hill forms an outlier of the upper rostratus beds. 



(6) At Harris's Pit the overturned mass of strata rests upon the 

 basal bed of the Upper Gault, with which the Cenomanian lime- 

 stone-lenticles have become intermingled. In neighbouring sections 

 a thin remnant of the overlying Upper Gault Clay is present in 

 normal sequence. 



(7) The fossils recorded by Messrs. Lamplugh & Walker as 

 occurring in the brachiopod-bed, of alleged Lower Greensand age, 

 came in part from the Cenomanian limestone and in part from the 

 basement-bed of the Upper Gault. The earlier of these strata would 

 be likely to yield specimens derived from the tardefurcata bed and 

 from lower zones, thus accounting for the supposed intermingled 

 character of the fauna of the brachiopod-bed. 



(8) It may be roughly estimated that the overturned mass was 

 originally some 250 yards in length, in north and south extension, 

 and upwards of 150 yards in breadth ; its westerly boundary has 

 not yet been reached in the sand- workings. 



(9) The inverted mass of strata became removed from its original 

 site during the glaciation of the district, as in the case of the trans- 

 ported masses at Biggleswade, Ely, and elsewhere. It was probably 

 derived from the higher, ground to the north or north-west of its 



