552 3111. E. "WETHERED ON THE INFERIOR 



foraminifera. The first t^'o are the most numerous, and the rock 

 may be said to be largelj' made up of them. 



Next follows the Cephalopoda-bed. It is 1^ foot thick and is an 

 argillaceous deposit containing belemnites. 



Of the calcareous bed which follows no thin section could be made, 

 and it will be referred to under the head of Insoluble llesidues. 

 This is succeeded b}' an argillaceous deposit containing lihyachonella 

 ciinoceplicda at the base. The beds above are also fairly fossiliferous, 

 and among them Mr. Buckman has determined the following * : — 

 JihyncJioiudla suhamjulata^ Rli. subdecorata , Terehratida peroualis, 

 T. Etherid(/ii, and Fholadomya Jldicula. 



Above the last bed "we come to about ten feet of argillaceous 

 strata in which are calcareous nodules made up of fragments of 

 spines, ossicles of crinoids, &c. The nodules are of the same yellow 

 colour and of the same structure as the lowest limestones of the 

 Inferior Oolite ; they are in fact the first indications of the Inferior- 

 Oolite limestones, and point to a gradual incoming of conditions 

 which were ultimately favourable to the existence of calcareous 

 organisms. 



It is at the top of the argillaceous beds containing the nodides 

 that the Transition Beds terminate, and coarse yellow limestones 

 appear which I regard as the base of the Pea-Grit Series. 



(c) The Pea-Grit Series. 



The term " Pea-Grit Series " will probably be challenged. The 

 name was originally given bj' Mr. Hugh Strickland t to beds 

 between the Midford Sands and Lower Preestones, and he describes 

 them as "■ pisolite " and " ferruginous oolite." The term was gene- 

 rally accepted till it was objected to by the late Mr. AYitchell ;|;. 

 He did so on the ground that the term Pea Grit, as defined by 

 Strickland, has caused "confusion" § : this because in the Stroud area 

 the large grains of the Pea Grit come in suddenly and show a well- 

 marked dividing-line between the pisolite and the oolite beneath. 

 This is perfectly true, and to Mr. Witchell belongs the credit of 

 pointing out the fact. But because beds differ lithologically in 

 different localities there seems no sufficient reason for altering a 

 well-known and accepted term. 



The normal section of the Pea-Grit Series is seen at Leckhampton 

 Hill, and in 1860 the late Dr. Wright, F.R.S., showed that there 

 were three divisions, which he marked A, B, C. The lowest of 

 these he described as *' a coarse brown ferruginous rock, composed 

 of large oolitic grains ; it is readily disintegrated by the frost, and 

 is of little economic value. About 20 feet thick" ||. The fact is 

 that this " coarse brown ferruginous rock " becomes less ferruginous 



* Proc. Cottesw. Natur. Field Club, vol. x. (1889-90) p. 96. 



t Quart. Journ. Geol Soc. vol. vi. (1850) p. 242. 



\ Ibid. vol. xlii. (1886) pp. 264-270. 



^ Tom., cit. p. 246. 



II Ibid. vol. xvi. (1860) p. 7. 



