6 INFERIOR OOLITE AMMONITES. 



This section contains the following zones : 



1 and 2. Parkinsoni-zone. 



3. Probably representative of Humphriesianum-zone. 



4. Perhaps equivalent to the Sauzei bed at Oborne. 



5. Sowerbyi-zone. 



6. Murchisonae-zone. 



7 — 23 (7 ?). Jurense-zone. 



This section and the one of Stroud Hill given below show how remarkable 

 is the difference in thickness between the rocks of the Inferior Oolite at 

 Bradford Abbas and Stroud, but that there is not really so very much difference 

 in the thickness of the Yeovil and the Cotteswold Sands. The Dorset section, 

 however, does not give the full depth of the sands at this point as it could not be 

 exactly ascertained right down to the Lias shales. 



These sands are extraordinarily well exposed near Bridport Harbour and at 

 the Cliffs at Burton Bradstock, and are estimated to be upwards of 200 feet thick. 

 Of the Cotteswold district I cannot speak from my own knowledge, but Mr. 

 Witchell gives the depth of the sands at Stroud Hill at about 110 feet, whilst 

 from Dr. Wright's section of Cleeve Hill, Gloucestershire, given in his 'Monograph 

 on Lias Ammonites/ page 155, they would appear to be only from 2 to 3 feet thick. 

 It would therefore seem that the depth of these sands varies more between different 

 localities in the Cotteswolds than it does between some parts of the Cotteswolds 

 and Dorset. 



The Yeovil Sands are of a more clayey tenacious character and of a darkish 

 blue colour towards the lower part. This may be well observed in a railway 

 cutting between Yeovil and Yeovil Junction. They are not greatly fossiliferous, 

 but I have met with Harpoceras Moorei (Lycett) in various places at the top, 

 middle, and lower parts, and Lytoceras jurense has also been obtained. These 

 fossils always occur in the bands of stone. At Yeovil Junction to the west of the 

 station is a fine quarry from which a considerable number of fossils have been 

 procured, while a few yards farther on in a field is a capital quarry of the Inferior 

 Oolite containing very small representatives of all the zones of that formation, very 

 much thinned out, so that its total depth does not here exceed about 6 feet ; a few 

 yards still farther on westwards one comes to the Fuller's Earth Clay. 



I here give part of a section of Stroud Hill, which I have taken from the 

 1 Geology of Stroud ' (the section faces page 5 of that work), by my friend, Mr. E. 

 Witchell, to whom I am indebted for much information regarding the Cotteswold 

 Hills. Below is his explanation according as I have numbered the beds. 



