vol.. .xvni. (i) WET.T.-SIXKTXO ON T.ANSDOWN, B.\TH 85 



The Iwttom-bed of the great Oohte is 2 feet thick, and 

 rests upon a curious band of bkie shale, called by the 

 workmen "the Cement Bed." On examination with a lens, 

 this bed was seen to contain several dark round polished-look- 

 ing oolite-granules, and a large Tcrebratulg., identified by 

 Mr S. S. Buckman as " Terehrntula decipiens, Dav., from the 

 Zigzag-Zone." Mr L. Richardson concurs in this identifica- 

 tion, but would hesitate to rely upon this evidence alone for 

 suggesting a date. 



Well-Sinking, No. 2. — At the same time as well No. 3 

 was being made, another was being sunk at the south-eastern 

 edge of the Lansdown plateau, overlooking Charlcombe Grove 

 .Farm, at a place 715 feet above Ordnance-datum. 



2. — Well-Sinking near Charlcombe Grove 



ft. ins. 



Great I Fissile Beds 34 



_. ,. - Beds of Oolite, more or less thick-bedded . . 63 



*-'°'"'^ I Coarse-grained Oolite 16 



Fuller '.s ( 



Earth \ day : seen 84 o 



. Only two fossils were found here — a small Gervillia and a 

 Cardium. The so-called " Cement-Bed " appeared to be absent, 

 although nodules of blue close-grained limestone occurred here 

 and there on its horizon. 



About 200 yards to the north-east of this last well, and at 

 the same altitude, 715 feet, is a quarry (Plate IX.) in which 

 the beds are comparable with those proved in the well. 



Quarry near Charlcombe Grove 



ft. ins. 



Great ( ^°'' ^"*^^ fissile beds . . . . . . . . . . 60 



- Massive-bedded coarsely-Oolitic stone . . . . 5 10 



Oolite j Bottom-bed: seen 17 



The dip is very slight on Lansdown. Therefore, since the 

 top of the well on the Golf Course is 750 feet above Ordnance- 

 datum, and the bottom of the quarry near Charlcombe Grove 

 about 702 feet, it would seem that the thickness of the Great 

 Oolite on the hill is about 48 feet. 



