364 
LOWER OOLITIC ROCKS OF ENGLAND : 
separates the divisions. Here and there we have a good base- 
line for the Forest Marble, and it may be possible on the 6-inch 
maps to separate the beds in a more systematic way than has been 
the case on the present Geological Survey Map. (See p. 271.) 
The general section of the Forest Marble beds near Cirencester 
is as follows : 
Cornbrash. 
Forest Marble -< 
FEET. 
Grey and greenish-grey clay with thin 
gritty layers (showing curious trails 
of invertebrata) ; and occasional beds 
of sandy, oolitic, and shelly lime- 
stone - - - - 30 to 40 
Here and there beds of sand and con- 
cretionary sandstone are met with - 10 to 15 
False-bedded shelly and oolitic lime- 
stone with clay-galls - 8 to 10 
Grey and blue marly clay and shale 
with " race," and thin layers and 
sometimes thicker inconstant beds 
of hard blue oolitic limestone and 
gritty limestone : at base, in places, 
the fossiliferous Bradford Clay - 30 to 45 
According to Prof. Hull the thickness of the Forest Marble at 
Coin Rogers is 40 feet, and at Tethury about 60 feet; while in 
the well-boring at the " Cotswold Brewery," Cirencester, it proved 
to be 108 feet. 
A small pit opened to a depth of about 8 feet by the road-side, 
north-east of Ewen, near Kemble, showed pale marly and racy 
clays with a band of shelly oolitic limestone, resting on pale shelly 
oolite (Great Oolite). From the clays I obtained the following 
species : 
Cypricardia caudata P 
Pecten vagans. 
Ostrea. 
Terebratula coarctata. 
maxillata. 
"Waldheimia cardium. 
digona. 
Rhynchonella concinna. 
spinosa, var. bradfordensis. 
Montlivaltia. 
By the Blue House, near the Thames and Severn Canal, noith 
of Furzen Leaze, clay lias been worked for repairing the Canal. 
The section, which I visited under the guidance of Prof. Allen 
Harker, was as follows : 
Forest Marble - 
Bradford Clay - 
Great Oolite - 
thin layers of gritty lime- 
Grey racy clay - 
Grey earthy and oolitic limestone. 
FT. IN. 
Here we do not find many fossils. Rhynchonella and spines of 
Echini may be obtained ; and Ostrea and Serpula have been 
recorded by Prof. Buckman.* Probably the same clay-bed is 
exposed in the Trewsbury quarry, although its thickness there is 
* Quart. Journ. Geol. Soc., Yol. xiv. p. 114. 
