VOL. XVII. (i) INFERIOR OOLITE— SOUTH COTTESWOLDS 79 



contain a " fairly constant series of argillaceous limestone (10 

 feet)," comparable apparently with the Ornithella-'Beds of 

 Dyrham. They yielded Pseudomonotis echinata (Sow.), Chlaniys 

 vagans (Sow.), Rhynchonella Smithi, Walker, Rhynchonella sp. 

 nov., and Ornithella ornithocephala (Sow.) 



There is not a sufficiency of evidence for dating precisely 

 the Fullers' Earth of the South Cotteswolds, but the following 

 remarks will show what is probable. 



Ammonites subcontr actus, Morris and Lycett, and Am- 

 monites Morrisi, Oppel, have been recorded from the Fullers'- 

 Earth Rock of Somerset and the Weatherstones and Shelly 

 Beds of Minchinhampton Common, near Stroud. If the 

 FuUers'-Earth Rock is equivalent to these Minchinhampton 

 beds, as this evidence seems to indicate, then the Ostrea- 

 acuminata-Clays — which occur just below the FuUers'-Earth 

 Rock in Somerset — must be equivalent to the FuUers'-Earth 

 clays with Ostrea-acuminata-Limestones in the northern portion 

 of the South Cotteswolds. Ostrea Knorri, Voltz, is abundant 

 at the base of the Fullers' Earth in the neighbourhood of 

 Doulting ; but, so far, has not been recorded from the South 

 Cotteswolds. It has been found, however, (first by Mr C. 

 Upton, and subsequently by the writer, in company with Mr 

 Upton), on the north side of the Slad Valley, and the writer 

 , has seen specimens — presumably from the Fullers' Earth — from 

 Cooper's Hill, near Gloucester, also in the Mid Cotteswolds. 



Specimens of Zigzagiceras have been procured from the 

 base of the Fullers' Earth between Midford and Coombe Hay 

 (in a cutting on the new railway) ; Mr Winwood has obtained 

 one, near to, if not identical with Zigzagiceras procerum (See- 

 bach), from the Fullers' Earth of Lansdown, near Bath ; while 

 as far north as Kingscote, a specimen — probably of the same 

 species — has been collected. 



Hence it would appear that the bottom-portion of the 

 Fullers' Earth, throughout the South Cotteswolds, is of zigzag 

 hemera. 



