106 F. L. Kitchin and J. Pr ingle — 



in which are nodules containing a remanie group of fossils ; hence the 

 transgressive strata are to be classified as rostratus Gault. The section 

 at Harris's Pit proves that still higher beds of the rostratus zone 

 were deposited. They are of a marly character and contain an 

 ammonite-fauna (the " catillus " fauna) represented in the Upper 

 Greensand of Wiltshire, below the Fecten asfer beds, and in the 

 Upper Greensand of the Isle of Wight just below the Chert beds. 

 These highest Gault strata are now only exposed at Shenley Hill 

 in the inverted mass at Harris's Pit. If present in situ anywhere 

 in the higher part of the hill they are concealed beneath the Drift. 



The bed of green sand observed by Mr. Lamplugh to be inter- 

 calated locally between the brachiopod-bed and the Gault Clay, 

 in the inverted mass, has yielded fossils which, so far as they are 

 known, indicate definitely a zonal jDosition above the Gault ; and . 

 we consider that this bed may be correlated provisionally with the 

 Pecten asper Greensand. The abrupt transition from the clay to the 

 sand suggests that the junction between them may represent 

 a line of non-sequence ; a considerable thickness of strata in the 

 more expanded arenaceous series of Wiltshire appears to be un- 

 represented here. The inconstant occurrence of this Upper Green- 

 sand bed, with rapid thickening, and the fact that where it is absent 

 the basal Cenomanian bed with brachiopods is separated from the 

 rostratus Gault only by a thin layer of ironstone of later origin, 

 point to a denudation of the uppermost part of the Selbornian 

 series prior to the deposition of the basal Cenomanian bed, with 

 a corresjoonding degree of non-sequence. This period of denudation 

 produced still more far-reaching effects in the region of the Cambridge 

 Greensand, in parts of Avhich, at least, the removal of much of the 

 Upper Gault was also involved. 



The next bed to be considered is the brachiopod-bed, which 

 consists of isolated limestone-lenticles, forming the lowest part of 

 the inverted mass. This affords ample evidence of its age and of 

 the conditions under which it was deposited. Its indigenous fauna 

 is that of the sub-zone of Cafopijgus columbarius at the base of the 

 Cenomanian stage as understood in this country ; and it has not 

 been proved that the bed contains fossils derived from older strata. 

 As already stated, the Lower Cretaceous species recorded by 

 Messrs. Lamplugh & Walker from the brachiopod-bed were in all 

 probability found in the basal bed of the Upper Gault, where they 

 would occur as derivatives. It is improbable that the strata which 

 formed the true source of these older fossils were exposed to 

 denudation at the time when the basal Cenomanian deposit was 

 laid down. 



We have remarked upon the close similarity of the limestone- 

 lenticles to the gritty limestone found in part of Northern France 

 at the base of the varians zone. Captain W. B. R. King, who sent 

 over specimens of this rock during the recent War, informs us that 

 it occurs at Matringhem in isolated lenticles occupying hollows in 



