114 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 17, 



at the "Blue quarry" on the canal near Cirencester, there is a dark 

 blue Forest Marble clay on the rock in question, and the masses of 

 stone beneath are so tough and blue-centred as to appear like a 

 stone of a different geological horizon ; these conditions will be made 

 plainer by comparing the following sections : — 



Section at Tetbury Road Station, near Cirencester. 



ft. in. 



1. Forest Marble, slates and sands 2 6 



2. Bradford Clay, full of fossils 7 



3. Great Oolite. A fine-grained and bright-coloured Oolite-stone, with 



oblique lamination becoming apparent after quarrying ; to bottom 10 



The Gas House Quarry, \ mile north of Cirencester. 



ft. in. 



1. Thin bed of broken brash 9 



2. Bradford Clay with Ter. digona, &c 2 



3. Freestone, with oblique laminze, separated into two stages at one 



end of the quarry by a thin band of clay 20 



4. Calcareous sandy bed with Ostrea Jurassica 9 



5. Bath Freestone, quarried in blocks, to bottom of quarry 15 



Mr. Flux's Quarry, only about 300 yards from the preceding, — 



ft. in. 



1. Blue Forest Marble clay 4 



2. White marlstone 9 



3. Blocks of Freestone, blue in the centre 3 



4. White Freestone, with oblique lamination, to bottom of quarry ... 6 



Blue House Quarry, on the Thames and Severn Junction Canal. 



ft. in. 



1. A stiff yellowish mottled clay with Ostrea 4 



2. Band of hard stone, full of shells and corals 2 



3. Dark-blue clay with several species of Serpula on 

 oysters, &c 3 6 



4. Band of yellow marl made up of decomposed shells, 

 = Bradford clay (?) 1 



5. Blocks of hard stone, blue in the centre, enclosing oolite pebbles . 6 



6. " Soft Freestone" of workmen ; not worked ; bottom of quarry. 



Probably 



Bradford 



clay. 



As regards the fossils of the Great Oolite, it will hardly be neces- 

 sary in this place to state more than general conclusions, inasmuch 

 as the excellent Monograph upon the Mollusca of this rock by Lycett 

 and Morris (Palseontograph. Soc.) leaves little to be desired respect- 

 ing their forms and specific details. Speaking of the prevailing fami- 

 lies, these authors have the following remark, which puts some im- 

 portant facts connected with the fauna of this rock before us in a 

 strong light :— 



" One of the most forcible impressions conveyed to the mind by a 

 survey of the Testacea of this formation, when compared with those 

 of the other members of the oolitic system, is the great scarcity of 



the Cephalopoda When the Phasianellse and Naticse, which are 



now known to be zoophagous, are added to our species of flesh- 

 eating Mollusca, it will at once be perceived how amply nature pro- 



