248 Dr. PiTTON on the Strata below the Chalk. 



Sand 

 the 



; (perhaps the representative of the Lower green-sand) said to be like that of 1 

 hill top. Masses of a calcareous conglomerate in the upper part j 



4. Fissile stone ; some of the upper beds of the Purbeck series : — 



a. Slaty limestone, abounding in Cypris and Cyclas, with smooth Paludinae, and 

 another acute spiral univalve. 



b. Fine-grained oolite in uniform globular particles, like the roe of fishes. 



(130.) Lower Green-sand. — This formation is nowhere prominent in the 

 Vale of Wardour, and scarcely observable throughout the greater part of it. 

 The ferruginous sands below the gault in the eastern portion of the valley 

 may not improbably be referable to some of the Wealden sands; but on the 

 road descending from the Pembroke Arms to Catherine Ford, a bed of 

 greenish sand occurs below the gault, which seems to be superior to the 

 Wealden strata ; and if this be continuous with a bed of sand which appears 

 at Penthurst and Fovantj it must belong to the marine beds; as I found at the 

 former place a Pecten and the stem of a Siphonia. Ochreous sand, with some 

 blue clay, to a total thickness of five or six feet, occurs likewise above the 

 Purbeck strata at Totterdale (Totteridge of the Ordnance Map), — a height 

 on the south of Tisbury, to which I shall hereafter have occasion to refer. 

 On the north side of the valley, sand of the same doubtful character occurs 

 immediately below the gault ; but a bright ochreous clay, in a corresponding 

 place between Apsell and Chicksgrove, is in my notes referred distinctly to 

 the Lower green-sand ; and a part of the sands from Fonthill Abbey to Stop 

 Beacon, may also belong to the same formation. On the whole, however, 

 the difference between the bulk of the Lower green-sand here, from that 

 which it exhibits in Kent, Sussex, and the Isle of Wight, is very remarkable, 

 and accords with the rapid thinning out of the formation westwards, on the 

 coast of Dorsetshire and Devon, 



(131.) Wealden. — The indications of the upper members of this group in 

 the Vale of Wardour are likewise indistinct, nor did 1 find here any of their 

 fossils ; but where the strata rise slowly from beneath the gault on the east, 

 under Fovant Wood, and thence by Catherine Ford and the sloping ground 

 towards Dinton and Teffont Magna, (PI. VIL fig. 3 ; and PI. X. a.. No. 13.,) 

 are traces, probably, of the Weald clay and Hastings sands ; the pond at 

 Dinton Parsonage, especially, resting on a bed which answers well to the 

 site of the Weald clay. These indications deserve notice, as they furnish 

 the only instance with which I am yet acquainted, of the occurrence of 

 the upper members of the W^ealden in the interior of England. The place 

 where these strata may be looked for with the greatest chance of success, 

 is on the descent from the plateau of the Upper green -sand to Catherine 



