C. E. De Ranee — Deposition of Cretaceous Strata. 247 



scene of numerous landslips. A species of Belemnite occurs in it, and 

 one of Pecten at Wambrook Valley. 



CoiD Stones. — These siliceous concretions occur immediately at the 

 base of the Fox Mould at Alston, Chardstock, and Black Ven ; 

 they are often six feet in length, and constitute the zone of Hoploparia 

 longimana. Of the former, 60 per cent, of the species are common to 

 the Whetstones and other Blackdown-beds, and about 32 per cent, 

 occur in the Folkestone Gault. 



Gault. — This deposit occurs at Golden Cap, Stonebarrow, Black 

 Ven, and Pinhay Cliff. It consists of dark grey-coloured stiff clay, 

 difficult to distinguish from some beds of the Lias, on which it rests. 

 At Black Ven, where it is perhaps best seen, it is divided from the 

 Cow Stones above by a few feet of yellow sand. A comparison of 

 the fossils found in this clay in the Museum of Practical Geology, 

 and in the collection of Mr. Day, now amalgamated with the former, 

 and in my own collection, with those of the Folkestone Gault, tends 

 to correlate the Dorsetshire Gault rather with the Lower Gault of 

 Folkestone than the Upper, in which case, supposing the Whetstones 

 in the Blackdown-beds to represent the Cow Stones, they and other 

 portions of the former may be the equivalents in time of the Upper 

 Gault. 



The Fox Mould, Cow Stones, and Gault are absent in the inland 

 Dorsetshire sections, at Lewston and Seamark Hills, and Buck- 

 ram, and the " Exogyra conica sand " rests upon a dark olive- 

 green coloured sand, without fossils and full of water. The sand is 

 particularly well seen at Hooke Park, a few miles east of Bea- 

 minster, which sand is probably the equivalent in time of the 

 Fox Mould of Lyme Eegis, which is not present in the White Cliff 

 section at Beer, where Sir Henry de la Beche considered the Fox 

 Mould to be represented by greenish-yellow and brown sands, 

 containing chert nodules, resting on green sands with concretions of 

 sandstones, the equivalents of the Cow Stones of Lyme. 



In the Beer section the Exogyra and Pecten asper zones are 

 represented by numerous bands of yellowish-brown sandstone, with 

 green earth, and chert seams, and nodules. The base of the Chalk 

 line is extremely compact and siliceous, and is the equivalent of the 

 Chalk with quartz grains of Penny s Toller and Lyme, and the " Beer 

 stone " of the quarries of Beer. 



Before leaving the description of the Cretaceous beds of this 

 area, it may be well to mention the vast sheets of more or less 

 angular gravels occurring on the tops of all the Cretaceous hills. 

 In the upper portion the flints are slightly rolled, and mixed with 

 numerous rolled quartz pebbles. In the lower portion the ground 

 often consists of masses of fractured chert, resting on a yellow clay, 

 occurring more or less in pot-holes, with long gnarled black-coated 

 flints. The whole series is well seen at Wambrook Valley, Alston, 

 Tytherleigh, Lewston, Seamark Hill, White-sheet Hill, Cotleigh 

 Hill, Pennys Toller, Hooke Park, and Golden Cap. 



Between Eggardon and Dorchester the country is composed of a 

 large sheet of Chalk, through which the Upper Greensand appears at 



