Oolitic Formations in the vicinity of Minchinhampton. 255 



(Orbigny), A. Lalandeanus (Orbigny), Mya margaritij era (Young) , 

 Ceromya V. scripta (Cardita, Buckman), Cardium, new species, 

 Anatina undulata (Sanguinolaria, Phillips), Mya dilata (Phillips). 

 As regards this neighbourhood, it may be stated as a general rule, 

 that where the lower beds of Great Oolite are shelly, they repose 

 immediately upon Fuller's earth ; in the other condition the base 

 is Stonesfield slate ; probably the fine mud of the latter deposit 

 was carried out to great depths almost beneath the region of 

 shells. Our Fuller's earth is very imperfectly exposed, nor have 

 any considerable number of species been obtained from it. The 

 little Ostrea acuminata is found in great masses, which nearly 

 compose the beds where it occurs. Not a single shell has been 

 found peculiar to these beds. 



The Inferior Oolite in the division of its beds does not differ 

 materially from the description given by Mr. Buckman in his 

 ' Geology of Cheltenham/ except towards the lower portion, which 

 is strikingly dissimilar. It is not our intention to do more than 

 allude to these conditions; a careful survey along the outer escarp- 

 ment of the Cotteswolds would be required to enable us to un- 

 derstand the changes of mineral character, fossil contents, and 

 perhaps thinning-out which certain beds must undergo in their 

 short course between Painswick and Crickley Hill. Many doubts 

 have been expressed by persons both in the metropolis and pro- 

 vinces as to the geological position of the rock from whence our 

 Great Oolite fossils are derived; these doubts would seem to 

 have arisen from a resemblance which portions of our rock and 

 its fossils bear to a certain bed of the Inferior Oolite near Chel- 

 tenham. 



Of the geological position of the rocks in our neighbourhood 

 no person who has examined them can entertain any doubt ; 

 our sections, both natural and artificial, are numerous and of 

 a decided character, affording what can rarely be seen elsewhere 

 in one view, a complete escarpment from the Great Oolite to 

 the Lias inclusive. The shells of the upper rag-stone agree 

 closely with those from the Cheltenham sections. The cream- 

 coloured marls and marly rock called " Fimbria bed/' have how- 

 ever disclosed a remarkable suite of shells which must not be 

 passed over in silence. The general aspect of these fossils, as 

 contrasted with those of the upper and lower rag-stones, is 

 striking. The association of genera strongly reminds us of the 

 Great Oolite. The genus Nerinea, which is very rarely seen in 

 the rag-stones, again reappears in vast profusion, to such an ex- 

 tent indeed that in some localities almost every fragment of marly 

 rock discloses sections of this extinct form. Accompanying these 

 are several species of small Cerithia, together with an equal variety 

 of the genus Chemnitzia } comprising some of the most slender 



